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        <title>MathCity.org</title>
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            <title>MathCity.org</title>
            <link>https://www.mathcity.org/</link>
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        <item>
            <title>Mathematics Conferences</title>
            <link>https://www.mathcity.org/conferences</link>
            <description>Mathematics Conferences
This page will no longer be updated. To spread the scope of this page, it has been merged with Mathematics Events.

Conferences can be ideal places to meet with professionals and present our work to live audience to get engage with them. It might be best place to find collaborators from with in country and outside of the country. On this page we have posted mathematics conferences occurring all over the country (PAKISTAN).</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:39:21 +0000</pubDate>
        </item>
        <item>
            <title>Khuram Ali Khan</title>
            <link>https://www.mathcity.org/khuram</link>
            <description>Khuram Ali Khan



Khuram Ali Khan, PhD

Associate Professor

Department of Mathematics

University of Sargodha

Sargodha - PAKISTAN.

Email: &lt;khuram@MathCity.org&gt;



Field of Research: Difference and functional equations, Real functions, Mathematical inequalities involving convex functions, Time Scales Calculus, Soft Sets</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 13 Jun 2025 12:03:59 +0000</pubDate>
        </item>
        <item>
            <title>Pakistan Mathematics Competitions (PMC) 2022 (1-3 April 2022)</title>
            <link>https://www.mathcity.org/events/sibau-pmo-2022</link>
            <description>Pakistan Mathematics Competitions (PMC) 2022 (1-3 April 2022)

[Pakistan Mathematics Competitions (PMC) 2022]
Mathematics Society – SIBAU is an active society, which has organized series of
successfully events in the past. These events were Inter University Mathematics
Olympiad 2014, 2015, National Mathematical Olympiad 2016, Pakistan National
Mathematical Olympiad 2017, Calculus Contest 2017, Calculus Contest 2018, National
Calculus Contest 2019, Pakistan National Mathematical Olympiad 2019 and…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 21 Mar 2022 13:15:06 +0000</pubDate>
        </item>
        <item>
            <title>Mathematical Events</title>
            <link>https://www.mathcity.org/events</link>
            <description>Mathematical Events

This page is dedicated to events related to field of mathematics, which includes conferences, seminars, workshops, games, occurring all over the country (PAKISTAN).
If you wish to add upcoming mathematical event on this page, please contact to</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 23 Mar 2025 06:48:21 +0000</pubDate>
        </item>
        <item>
            <title>22nd International Pure Mathematics Conference on Algebra, Analysis and Geometry (23 to 25 ...</title>
            <link>https://www.mathcity.org/events/22nd-ipmc-2021</link>
            <description>22nd International Pure Mathematics Conference on Algebra, Analysis and Geometry (23 to 25 August 2021)

[22nd International Pure Mathematics Conference 2021 (22nd IPMC 2021) on Algebra, Analysis and Geometry]

It will provide a stimulating opportunity to interact with experts from various countries in a variety of branches of pure mathematics. The conference will be organized ONLINE.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 13 Jul 2021 10:50:35 +0000</pubDate>
        </item>
        <item>
            <title>1st SIBAU-NU International Workshop on Matrix Analysis and Linear Algebra (15-17 October 2021)</title>
            <link>https://www.mathcity.org/events/sibau-nu-workshop-2021</link>
            <description>1st SIBAU-NU International Workshop on Matrix Analysis and Linear Algebra (15-17 October 2021)

[1st SIBAU-NU International Workshop on Matrix Analysis and Linear Algebra]

	*   Conference Name: 1st SIBAU-NU International Workshop on Matrix Analysis and Linear Algebra
	*  Venue: Online
	*  Organizer: Department of Mathematics, Sukkur IBA University, (SIBAU)-Pakistan and Naresuan University, (NU)-Thailand</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 09 Jul 2021 18:34:07 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Fall 2016)</title>
            <link>https://www.mathcity.org/atiq/fa16-mth322</link>
            <description>~~DISCUSSION:off~~

MTH322: Real Analysis II (Fall 2016)
Do you have questions or comments? Please use Discussion at the end of this page.

This course is offered to MSc, Semester III at Department of Mathematics, COMSATS Institute of Information Technology, Attock campus. The is course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notion included in</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:40:09 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Fall 2017)</title>
            <link>https://www.mathcity.org/atiq/fa17-mth322</link>
            <description>MTH322: Real Analysis II (Fall 2017)

This course is offered to MSc, Semester III at Department of Mathematics, COMSATS Institute of Information Technology, Attock campus. The is course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notion included in</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:40:10 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Fall 2018)</title>
            <link>https://www.mathcity.org/atiq/fa18-mth322</link>
            <description>MTH322: Real Analysis II (Fall 2018)

This course is offered to MSc, Semester II at Department of Mathematics, COMSATS University Islamabad, Attock campus. This course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notion included in</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:40:11 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Fall 2019)</title>
            <link>https://www.mathcity.org/atiq/fa19-mth322</link>
            <description>MTH322: Real Analysis II (Fall 2019)

This course is offered to MSc, Semester II at Department of Mathematics, COMSATS University Islamabad, Attock campus. This course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers. these notions included in</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:40:12 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Fall 2020)</title>
            <link>https://www.mathcity.org/atiq/fa20-mth322</link>
            <description>MTH322: Real Analysis II (Fall 2020)

This course is offered to MSc, Semester II at Department of Mathematics, COMSATS University Islamabad, Attock campus. This course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notion included in</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:40:14 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Fall 2021)</title>
            <link>https://www.mathcity.org/atiq/fa21-mth322</link>
            <description>MTH322: Real Analysis II (Fall 2021)

This course is offered to MSc, Semester II at Department of Mathematics, COMSATS University Islamabad, Attock campus. This course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notion included in $\int_{1}^{\infty }{{{x}^{-p}} dx}$$p$$f\in \mathcal{R}[a,b]$$b\ge a$$f(x)\ge 0$$x\ge a$$\int_{a}^{\infty }{f(x) dx}$$M&gt;0$$\int\limits_{a}^{b}{f(x)\,dx} \le M$$b\ge a$$f\in \mathcal{R}[a,b]$$b\ge a$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 30 Dec 2021 19:16:17 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Spring 2017)</title>
            <link>https://www.mathcity.org/atiq/sp17-mth322</link>
            <description>~~DISCUSSION:closed~~

MTH322: Real Analysis II (Spring 2017)
Do you have questions or comments? Please use Discussion at the end of this page.

This course is offered to MSc, Semester III at Department of Mathematics, COMSATS Institute of Information Technology, Attock campus. The is course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notion included in</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:40:35 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Spring 2019)</title>
            <link>https://www.mathcity.org/atiq/sp19-mth322</link>
            <description>MTH322: Real Analysis II (Spring 2019)

This course is offered to MSc, Semester II at Department of Mathematics, COMSATS University Islamabad, Attock campus. This course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notion included in</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:40:39 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Spring 2022)</title>
            <link>https://www.mathcity.org/atiq/sp22-mth322</link>
            <description>MTH322: Real Analysis II (Spring 2022)

This course is offered to BS, Semester VI at Department of Mathematics, COMSATS University Islamabad, Attock campus. This course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notion included in</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 13 Apr 2022 05:45:43 +0000</pubDate>
        </item>
        <item>
            <title>MTH322: Real Analysis II (Spring 2023)</title>
            <link>https://www.mathcity.org/atiq/sp23-mth322</link>
            <description>MTH322: Real Analysis II (Spring 2023)

[MTH322: Real Analysis II (Spring 2023)]
This course is offered to BS, Semester VI at Department of Mathematics, COMSATS University Islamabad, Attock campus. This course need rigorous knowledge of continuity, differentiation, integration, sequences and series of numbers, that is many notions included in $f\in \mathcal{R}[a,b]$$b\ge a$$f(x)\ge 0$$x\ge a$$\int_{\,a}^{\,\infty }{f(x)\,dx}$$M&gt;0$$\int\limits_{a}^{b}{f(x)\,dx}\leq M$$b\ge a$$f(x)$$g(x)$$x&gt;a$$\li…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 15 Jun 2023 01:08:47 +0000</pubDate>
        </item>
        <item>
            <title>5th UMT International Conference on Pure and Applied Mathematics, Lahore (March 29th to 31st, 2019)</title>
            <link>https://www.mathcity.org/conferences/5th-uicpam-2019-lahore</link>
            <description>5th UMT International Conference on Pure and Applied Mathematics, Lahore (March 29th to 31st, 2019)

[5th UICPAM-2019]

UMT International Conference on Pure and Applied Mathematics (UICPAM) was successfully held for last four years. The support and participation of our membership and scholar promote it possible for UICPAM continuely to be held in University of Management and Technology, Lahore during March 29-31, 2019.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:44 +0000</pubDate>
        </item>
        <item>
            <title>11th International Pure Mathematics Conference 2010, Islamabad (6-8 August, 2010)</title>
            <link>https://www.mathcity.org/conferences/11th_international_pure_mathematics_conference_2010_islamabad</link>
            <description>11th International Pure Mathematics Conference 2010, Islamabad (6-8 August, 2010)

[Faisal Mosque, Islamabad]

	*  Name of conference: 11th International Pure Mathematics Conference 2010
	*  Palace: National Center for Physics, Islamabad - PAKISTAN.
	*   Date: 6 - 8 August 2010</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:37 +0000</pubDate>
        </item>
        <item>
            <title>12th International Pure Mathematics Conference 2011, Islamabad (29-31 July, 2011)</title>
            <link>https://www.mathcity.org/conferences/12th_international_pure_mathematics_conference_2011_islamabad</link>
            <description>12th International Pure Mathematics Conference 2011, Islamabad (29-31 July, 2011)

[View of Margalla Hills, Islamabad.]

	*  Name of conference: 12th International Pure Mathematics Conference 2011
	*  Palace: Hotel Margalla, Islamabad - PAKISTAN.
	*   Date: 29--31 July, 2011
	*   Registration Deadline:</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:37 +0000</pubDate>
        </item>
        <item>
            <title>13th International Pure Mathematics Conference 2012, Islamabad (1-3 September, 2012)</title>
            <link>https://www.mathcity.org/conferences/13th_international_pure_mathematics_conference_2012_islamabad</link>
            <description>13th International Pure Mathematics Conference 2012, Islamabad (1-3 September, 2012)



	*  Name of conference: 13th International Pure Mathematics Conference 2012
	*  Palace: Hotel Margalla, Islamabad - PAKISTAN.
	*   Date: 1--3 September, 2012
	*</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:39 +0000</pubDate>
        </item>
        <item>
            <title>15th International Pure Mathematics Conference 2014, Islamabad (28-30 August, 2014)</title>
            <link>https://www.mathcity.org/conferences/15th_international_pure_mathematics_conference_2014_islamabad</link>
            <description>15th International Pure Mathematics Conference 2014, Islamabad (28-30 August, 2014)



	*  Name of conference: 15th International Pure Mathematics Conference 2014
	*  Palace: Hotel Margalla, Islamabad - PAKISTAN.
	*   Date: 28--30 August, 2014
	*   Registration Deadline:</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:40 +0000</pubDate>
        </item>
        <item>
            <title>18th International Pure Mathematics Conference 2017, Islamabad (4-6 August 2017)</title>
            <link>https://www.mathcity.org/conferences/18th-pmc-islamabad</link>
            <description>18th International Pure Mathematics Conference 2017, Islamabad (4-6 August 2017)

[18th PMC Margalla Islamabad, 2017]

It will provide a stimulating opportunity to meet experts from various countries in a variety of branches of mathematics. The entire conference will be organized under one roof at a hotel, in the modern, peaceful, and beautiful federal capital of Pakistan located at the footsteps of the scenic Margalla Hills. We will be able to offer you subsidized accommodation, free meals, fre…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:40 +0000</pubDate>
        </item>
        <item>
            <title>19th International Pure Mathematics Conference 2018, Islamabad (17-19 August 2018)</title>
            <link>https://www.mathcity.org/conferences/19th-pmc-islamabad</link>
            <description>19th International Pure Mathematics Conference 2018, Islamabad (17-19 August 2018)

[18th PMC Margalla Islamabad, 2017]

This conference will provide a stimulating opportunity to meet experts from various countries in a variety of branches of pure mathematics. The entire conference will be organized at the modern, peaceful and beautiful federal capital of Pakistan. There will be free lodging for foreign participants in a first class hotel. Several free recreational trips will be organized in and…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:41 +0000</pubDate>
        </item>
        <item>
            <title>5th International Conference on Pure and Applied Mathematics, UoS Sargodha (24-25 February 2020)</title>
            <link>https://www.mathcity.org/events/5th-icpam-2020-sargodha</link>
            <description>5th International Conference on Pure and Applied Mathematics, UoS Sargodha (24-25 February 2020)

[5th International Conference on Pure and Applied Mathematics, UoS Sargodha (24-25 February 2020]

	*   Conference Name: 5th International Conference on Pure and Applied Mathematics
	*  Venue: Department of Mathematics, University of Sargodha, Sargodha-PAKISTAN.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:42:34 +0000</pubDate>
        </item>
        <item>
            <title>Atiq ur Rehman, PhD</title>
            <link>https://www.mathcity.org/atiq</link>
            <description>Atiq ur Rehman, PhD




Atiq ur Rehman, PhD

Associate Professor (Tenured)

Department of Mathematics

COMSATS University Islamabad, Attock Campus

Kamra Road, Attock - PAKISTAN.

Email: &lt;Atiq@MathCity.org&gt;, &lt;atiq@cuiatk.edu.pk&gt;

Field of Research: Difference and functional equations, Real functions, Inequalities in monotonic and convex functions</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 01 Feb 2026 14:25:54 +0000</pubDate>
        </item>
        <item>
            <title>Mathematics 11 for FSc ICS (NBF)</title>
            <link>https://www.mathcity.org/math-11-nbf</link>
            <description>Mathematics 11 for FSc ICS (NBF)

[A Textbook of Mathematics for Class XI]
Model Textbook of Mathematics for Class XI is published by National Book Foundation (NBF), Islamabad, Pakistan. NBF can be considered as Federal Textbook Board Islamabad. The book has total of nine (9) chapters. This book is written by Dr. Khalid Mahmood, Dr. Saleem Ullah Satti, M Dabeer Mughal, Dr. Naveed Akmal and Dr. Shahzad Ahmad.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Feb 2026 14:30:09 +0000</pubDate>
        </item>
        <item>
            <title>Mathematics 12 for FSc ICS (NBF)</title>
            <link>https://www.mathcity.org/math-12-nbf</link>
            <description>Mathematics 12 for FSc ICS (NBF)

[Textbook of Mathematics for Class 12]
Textbook of Mathematics for Class XII is published by National Book Foundation (NBF), Islamabad, Pakistan. NBF can be considered as Federal Textbook Board Islamabad. The book has total of ten (10) chapters. Dr, Khalid Mahmood is the Managing Author. Saleem Ullah Satti, Muhammad Dabeer Mughal, Dr. Naveed Akmal and Muhammad Anwar ul Haq are the co-authors of the book.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 16 Feb 2026 07:08:57 +0000</pubDate>
        </item>
        <item>
            <title>1st UMT National Conference on Pure and Applied Mathematics, Lahore (7-8 March, 2015)</title>
            <link>https://www.mathcity.org/conferences/1st_uncpam-2015</link>
            <description>1st UMT National Conference on Pure and Applied Mathematics, Lahore (7-8 March, 2015)



	*  Name of conference: 1st UMT National Conference on Pure and Applied Mathematics
	*  Palace: University of Management and Technology, Lahore - PAKISTAN.
	*</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:42 +0000</pubDate>
        </item>
        <item>
            <title>1st LGU National Conference on Pure and Applied Mathematics (17-18 May 2017)</title>
            <link>https://www.mathcity.org/conferences/1st-lgu-ncpam</link>
            <description>1st LGU National Conference on Pure and Applied Mathematics (17-18 May 2017)

[Lahore Garrison University]

	*   Conference Name: 1st LGU National Conference on Pure and Applied Mathematics
	*  Venue: Lahore Garrison University, DHA Phase IV, Lahore-PAKISTAN. 
	*  Conference Date:</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:41 +0000</pubDate>
        </item>
        <item>
            <title>1st National Conference on Pure and Applied Mathematics UoS Sargodha (04-05 May 2017)</title>
            <link>https://www.mathcity.org/conferences/1st-ncpam-2017</link>
            <description>1st National Conference on Pure and Applied Mathematics UoS Sargodha (04-05 May 2017)



	*   Conference Name: 1st National Conference on Pure and Applied Mathematics
	*  Venue: Department of Mathematics, University of Sargodha, Sargodha-PAKISTAN. 
	*</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:41 +0000</pubDate>
        </item>
        <item>
            <title>3rd National Conference on Mathematical Sciences, IIU, Islamabad (27-28 April 2017)</title>
            <link>https://www.mathcity.org/conferences/3rd-cms-2017</link>
            <description>3rd National Conference on Mathematical Sciences, IIU, Islamabad (27-28 April 2017)

[3rd CMS 2017]

	*  Name of conference: 3rd National Conference on Mathematical Sciences
	*  Venue: Allama Iqbal Auditorium, Faisal Mosque Campus (old Campus) IIU, Islamabad, PAKISTAN.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:43 +0000</pubDate>
        </item>
        <item>
            <title>4th International Conference on &quot;Recent Developments in Fluid Mechanics&quot;, QAU, ...</title>
            <link>https://www.mathcity.org/conferences/4th_international_conference_on_recent_developments_in_fluid_mechanics_qau_islamabad</link>
            <description>4th International Conference on &quot;Recent Developments in Fluid Mechanics&quot;, QAU, Islamabad (09-11 August 2010)

[Bab-e-Quaid, Islamabad]

	*  Name of conference: 4th International Conference on “Recent Developments in Fluid Mechanics”
	*  Palace: Quaid-i-Azam University, Islamabad - PAKISTAN.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:43 +0000</pubDate>
        </item>
        <item>
            <title>1st International Conference on Advancements in Mathematics, CIIT Attock (11-13 February, 2015)</title>
            <link>https://www.mathcity.org/conferences/icam-2015</link>
            <description>1st International Conference on Advancements in Mathematics, CIIT Attock (11-13 February, 2015)



	*  Name of conference: 1st International Conference on Advancements in Mathematics
	*  Palace: COMSATS Institute of Information Technology (New Campus), Attock - PAKISTAN.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:47 +0000</pubDate>
        </item>
        <item>
            <title>International Conference on Computing and Mathematical Sciences, IBA Sukkur (February 25-26, 2017)</title>
            <link>https://www.mathcity.org/conferences/iccms-2017</link>
            <description>International Conference on Computing and Mathematical Sciences, IBA Sukkur (February 25-26, 2017)

[IBA Shukar]
The selected papers will be published in SIBA Journal of Computing and Mathematical Sciences (JCMS).
	*  Name of conference: International Conference on Computing and Mathematical Sciences</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:49 +0000</pubDate>
        </item>
        <item>
            <title>International Conference on Mathematics and Its Applications GCU Lahore, Pakistan (November ...</title>
            <link>https://www.mathcity.org/conferences/icma-gcul-2017</link>
            <description>International Conference on Mathematics and Its Applications GCU Lahore, Pakistan (November 13-15, 2017)

[ICMA GCU Lahore]

	*   Conference Name: International Conference on Mathematics and Its Applications
	*  Registration Deadline: September 30, 2017
		*  Contact Dr. Shahid Ahmad (</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:49 +0000</pubDate>
        </item>
        <item>
            <title>2nd International Conference on Pure and Applied Mathematics UoS Sargodha (November 26-27, 2016)</title>
            <link>https://www.mathcity.org/conferences/icpam-2016</link>
            <description>2nd International Conference on Pure and Applied Mathematics UoS Sargodha (November 26-27, 2016)



	*   Conference Name: International Conference on Pure and Applied Mathematics
	*  Registration Deadline: Not known ( &lt;https://docs.google.com/forms/d/16T2QVT-aRuKeFIItMLxTDd_omsQLJ_5cIryhkSmyDx4/edit?usp=sharing&gt; )
	*  Conference Date: November 26-27, 2016</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:50 +0000</pubDate>
        </item>
        <item>
            <title>3rd International Conference on Pure and Applied Mathematics UoS Sargodha (November 10-11, 2017)</title>
            <link>https://www.mathcity.org/conferences/icpam-2017</link>
            <description>3rd International Conference on Pure and Applied Mathematics UoS Sargodha (November 10-11, 2017)

[3rd ICPAM]

	*   Conference Name: International Conference on Pure and Applied Mathematics
	*  Registration Deadline: October 15, 2017 ( &lt;http://icpam.uos.edu.pk/#registration&gt; )
	*  Conference Date: November 10-11, 2017</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:50 +0000</pubDate>
        </item>
        <item>
            <title>International Conference on Recent Advances in Applied Mathematics, CIIT, Lahore (Dec 17-18, 2015)</title>
            <link>https://www.mathcity.org/conferences/international_conference_on_recent_advances_in_applied_mathematics_ciit_lahore</link>
            <description>International Conference on Recent Advances in Applied Mathematics, CIIT, Lahore (Dec 17-18, 2015)

[CIIT Lahore]

	*  Name of conference: International Conference on Recent Advances in Applied Mathematics
	*  Palace: COMSATS Institute of Information Technology, Lahore - PAKISTAN.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:52 +0000</pubDate>
        </item>
        <item>
            <title>International Conference on Mathematical Inequalities and Application 2010, ASSMS, Lahore (7-13 ...</title>
            <link>https://www.mathcity.org/conferences/mathematical_inequalities_and_applications_2010_assms</link>
            <description>International Conference on Mathematical Inequalities and Application 2010, ASSMS, Lahore (7-13 March 2010)

[ASSMS, old building in New Muslim Town, Lahore-PAKISTAN]

	*   Conference Name: International Conference on Mathematical Inequalities and Application 2010
	*  Registration Deadline: January 30, 2010</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:52 +0000</pubDate>
        </item>
        <item>
            <title>National Conference on Mathematics and Applications, UoS Sargodha (09-10 April 2018)</title>
            <link>https://www.mathcity.org/conferences/ncma-2018</link>
            <description>National Conference on Mathematics and Applications, UoS Sargodha (09-10 April 2018)



	*   Conference Name: 2018 National Conference on Mathematics and Applications
	*  Venue: Department of Mathematics, University of Sargodha, Sargodha-PAKISTAN. 
	*</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:58 +0000</pubDate>
        </item>
        <item>
            <title>One Day International Symposia on Pure and Applied Mathematics UoS Sargodha (January 27, 2014)</title>
            <link>https://www.mathcity.org/conferences/one_day_international_symposia_on_pure_and_applied_mathematics_sargodha</link>
            <description>One Day International Symposia on Pure and Applied Mathematics UoS Sargodha (January 27, 2014)



	*   Conference Name: One Day International Symposium on Pure and Applied Mathematics
	*  Registration Deadline: January 18, 2014
	*  Conference Date: January 27, 2014</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:42:02 +0000</pubDate>
        </item>
        <item>
            <title>Second Conference on Mathematical Sciences (SCMS-2013), International Islamic University, ...</title>
            <link>https://www.mathcity.org/conferences/second_conference_on_mathematical_sciences_islamabad</link>
            <description>Second Conference on Mathematical Sciences (SCMS-2013), International Islamic University, Islamabad, Pakistan (1-2 November 2013)



	*  Conference Name: Second Conference on Mathematical Sciences (SCMS-2013)
	*  Final submission of Abstract/Full Paper:</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:42:02 +0000</pubDate>
        </item>
        <item>
            <title>1st National Conference on Mathematics, Baba Guru Nanak University, Nankana Sahib, Pakistan ...</title>
            <link>https://www.mathcity.org/events/1st-ncm-2025</link>
            <description>1st National Conference on Mathematics, Baba Guru Nanak University, Nankana Sahib, Pakistan (10-11 April 2025)



	*   Conference Name: 1st National Conference on Mathematics
	*  Venue: Department of Mathematics, Baba Guru Nanak University, Nankana Sahib, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 23 Mar 2025 07:06:53 +0000</pubDate>
        </item>
        <item>
            <title>7th International Conference on Pure and Applied Mathematics, UoS Sargodha (17-18 April 2025)</title>
            <link>https://www.mathcity.org/events/icpam-2025</link>
            <description>7th International Conference on Pure and Applied Mathematics, UoS Sargodha (17-18 April 2025)



	*   Conference Name: 7th International Conference on Pure and Applied Mathematics
	*  Venue: Department of Mathematics, University of Sargodha, Sargodha-PAKISTAN.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 23 Mar 2025 07:07:24 +0000</pubDate>
        </item>
        <item>
            <title>Solutions: Math 12 NBF</title>
            <link>https://www.mathcity.org/math-12-nbf/sol</link>
            <description>Solutions: Math 12 NBF

[Solutions of Textbook of Mathematics 12]
Solutions of “Textbook of Mathematics 12 published by National Book Foundation (NBF), Islamabad, Pakistan”. NBF can be considered as Federal Textbook Board Islamabad. 
This comprehensive guide, Solutions for Mathematics 12, serves as a definitive resource for students mastering the advanced HSSC curriculum. Published by the National Book Foundation (NBF), it bridges the gap between complex theory and practical application. The tex…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 04 May 2026 16:11:21 +0000</pubDate>
        </item>
        <item>
            <title>PPSC Paper 2021 (Lecturer in Mathematics)</title>
            <link>https://www.mathcity.org/ppsc/ppsc-maths-2021</link>
            <description>PPSC Paper 2021 (Lecturer in Mathematics)

[PPSC Paper 2011 (Lecturer in Mathematics)]

On this page, we have given question from old (past) paper of Lecturer in Mathematics conducted in year 2021. This is a MCQs paper and answers are given at the end of the paper. At the end of the PDF is also given to download. This paper is provided by Ms. \(2018\)$4$\(6\)$8$$10$\(X\)\(Y\)\(X\times Y\)\(\parallel (x,y) \parallel=\parallel x\parallel+\parallel y\parallel, \,\forall \, (x,y)\in X \times Y\)\(f(…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 23 Aug 2022 17:04:49 +0000</pubDate>
        </item>
        <item>
            <title>About Us</title>
            <link>https://www.mathcity.org/about_us</link>
            <description>About Us

The only purpose of this website is to help students to learn mathematics. This site contains material for the students of  F.Sc., B.Sc., M.Sc., M.Phil. and Ph.D, in the subject of mathematics. The website division has been made according to the different classes for simple navigation. For example, student or teacher searching for notes of F.Sc may see</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 03 Apr 2025 19:07:53 +0000</pubDate>
        </item>
        <item>
            <title>FSc Part 1 (Mathematics): KPK</title>
            <link>https://www.mathcity.org/fsc-part1-kpk</link>
            <description>FSc Part 1 (Mathematics): KPK

[A Textbook of Mathematics for Class XI]
A Textbook of Mathematics for Class XI is published by Khybar Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan. The book has total of twelve (12) chapters. This book is written by Prof. Dr. Gulzar Ali Khan, Prof. Dr. Islam Noor and Prof. Dr. Muhammad Shah.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 12 Dec 2023 17:09:07 +0000</pubDate>
        </item>
        <item>
            <title>Home</title>
            <link>https://www.mathcity.org/home</link>
            <description>Home

Welcome to MathCity.org. Please browse the website by using navigation bar or search the website.




More Quotes :---: MathCity.org


Updates

	*  | FSc (PECTAA) | Solutions of the many exercises of Mathematics 11 (by PECTAA) has been add. read more for download NEW
	*  | Notes | Mechanics III (Analytic Dynamics II) by Dr Babar Ahmad has been added in the notes section.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 24 Mar 2026 18:10:06 +0000</pubDate>
        </item>
        <item>
            <title>FSc/ICS Part 1 (Mathematics): KPK</title>
            <link>https://www.mathcity.org/math-11-kpk</link>
            <description>FSc/ICS Part 1 (Mathematics): KPK

[A Textbook of Mathematics for Class XI]
A Textbook of Mathematics for Class XI is published by Khybar Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan. The book has total of twelve (12) chapters. This book is written by Prof. Dr. Gulzar Ali Khan, Prof. Dr. Islam Noor and Prof. Dr. Muhammad Shah.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 06 Feb 2024 13:20:19 +0000</pubDate>
        </item>
        <item>
            <title>Mathematics 11 (PECTAA)</title>
            <link>https://www.mathcity.org/math-11-pectaa</link>
            <description>Mathematics 11 (PECTAA)

[Mathematics 11 for FSc and ICS (PECTAA)]
Mathematics 11 is is based on Updated/Revised National Curriculum of Pakistan 2023 and has been approved by the Punjab Education, Curriculum, Training and Assessment Authority (PECTAA) previously known as Punjab Textbook Board (PTB).  This is a textbook for all the boards of Punjab for 11th class (FSc or ICS Part 1 or HSSC-I). The book has total of fourteen (14) units.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Jul 2025 06:50:20 +0000</pubDate>
        </item>
        <item>
            <title>Open Notes</title>
            <link>https://www.mathcity.org/open-notes</link>
            <description>Open Notes

What are Open Notes?


[Open Notes on Mathematics]
We&#039;re planning to release notes and books related to mathematics. We&#039;ll give readers and teachers the original files. This way, they can update the materials to fit their own needs. We call these resources “Open Notes</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 28 Jun 2025 19:08:38 +0000</pubDate>
        </item>
        <item>
            <title>International Conference on Differential Equations and Applications, LUMS Lahore (May 26-28 2016)</title>
            <link>https://www.mathcity.org/conferences/differential_equations_and_applications_may_26-28_2016_lums_lahore</link>
            <description>International Conference on Differential Equations and Applications, LUMS Lahore (May 26-28 2016)

[Main Building LUMS, Lahore]

	*  Name of conference: Differential Equations and Applications
	*  Palace: Lahore University of Management Sciences (LUMS), Lahore - PAKISTAN.
	*  Date:</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:41:47 +0000</pubDate>
        </item>
        <item>
            <title>Mathematics Olympiad 2019 Sukkur IBA (11-13 November 2019)</title>
            <link>https://www.mathcity.org/events/mathematics-olympiad-2019-sukkur-iba</link>
            <description>Mathematics Olympiad 2019 Sukkur IBA (11-13 November 2019)

[Mathematics Olympiad 2019]
Mathematical Olympiad is a contest of mathematics among the students. It is a very healthy activity to promote and learn mathematics. Contents for the test are as follows:

	*  Qudratic equations and expressions</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:42:33 +0000</pubDate>
        </item>
        <item>
            <title>FSc Part 1 Mathematics Notes/Solutions</title>
            <link>https://www.mathcity.org/fsc-part1-ptb/sol</link>
            <description>FSc Part 1 Mathematics Notes/Solutions

[FSc Part1 PTB Book Cover]
Notes (Solutions) of Textbook of Algebra and Trigonometry Class XI (Mathematics FSc Part 1 or HSSC-I), Punjab Textbook Board (PTB) Lahore.
 There are fourteen chapters in this book and we have work hard to make easy and suitable solution for students and teachers so that it help them learn things quickly and easily. Please click on a desire chapter to view the solution of any particular exercise. This work is licensed under a Cre…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 08 Aug 2023 17:59:03 +0000</pubDate>
        </item>
        <item>
            <title>FSc Part 1 Mathematics Notes/Solutions</title>
            <link>https://www.mathcity.org/fsc/fsc_part_1_solutions</link>
            <description>FSc Part 1 Mathematics Notes/Solutions
This is an old book. Notes of new book are available at following link: &lt;https://www.mathcity.org/math-11-pectaa&gt;

[FSc Part1 PTB Book Cover]
Notes (Solutions) of Textbook of Algebra and Trigonometry Class XI (Mathematics FSc Part 1 or HSSC-I), Punjab Textbook Board (PTB) Lahore.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Jul 2025 09:10:04 +0000</pubDate>
        </item>
        <item>
            <title>FSc/ICS Part 2 Solutions</title>
            <link>https://www.mathcity.org/fsc/fsc_part_2_solutions</link>
            <description>FSc/ICS Part 2 Solutions

[Calculus and Analytic Geometry, MATHEMATICS 12]
Notes (Solutions) of Calculus and Analytic Geometry, MATHEMATICS 12 (Mathematics FSc/ICS Part 2 or HSSC-II), Punjab Text Book Board Lahore.
 There are seven units in this book and we have work hard to make easy and suitable solutions for students and teachers so that it help them learn things quickly and easily. Please click on a desire unit to view the solution of any particular exercise. This work is licensed under a Cr…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 21 Mar 2025 18:12:01 +0000</pubDate>
        </item>
        <item>
            <title>Pakistan Journal of Mathematical Sciences</title>
            <link>https://www.mathcity.org/journals/pjms</link>
            <description>Pakistan Journal of Mathematical Sciences

[Pakistan Journal of Mathematical Sciences]
Pakistan Journal of Mathematical Sciences (PJMS) is an open access, peer-reviewed journal. The short title or abbreviation of the journal is “Pak. J. Math. Sci.” Two issues will be published in a year, that is, it will be published biannually. One issue will cover from January to June and other issue will cover from July to December.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 13 Nov 2021 17:52:54 +0000</pubDate>
        </item>
        <item>
            <title>Definitions: Mathematics 11 NBF</title>
            <link>https://www.mathcity.org/math-11-nbf/definitions</link>
            <description>Definitions: Mathematics 11 NBF

Model Textbook of Mathematics for Class XI is published by National Book Foundation (NBF), Islamabad, Pakistan. NBF can be considered as Federal Textbook Board Islamabad. The book has total of nine (9) chapters.

Definition of the book provide the quick overview of the book.$x+iy$$x,y\in\mathbb{R}$$i^2=1$$\mathbb{C}$$x+i y$$x$$y$$x$$y$$Re(z)=x$$Im(z)=y$$z=x+i y$$\bar{z}$$\bar{z}=x-i y$$z=x+i y$$|z|$$|z|=\sqrt{x^{2}+y^{2}}$$z=x+iy$$Re(z)=x$$Im(z)=y$$Re(z^{-1})= \d…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 10 Jul 2024 18:51:53 +0000</pubDate>
        </item>
        <item>
            <title>MCQs: Math 11 NBF</title>
            <link>https://www.mathcity.org/math-11-nbf/mcqs</link>
            <description>MCQs: Math 11 NBF
Multiple Choice Questions (MCQs) of the Model Textbook of Mathematics for Class XI is published by National Book Foundation (NBF), Islamabad, Pakistan. NBF can be considered as Federal Textbook Board Islamabad. 
Unit 01: Complex Numbers
$\operatorname{part}(\mathrm{s})$$z$$z$$(0,0)$$(1,0)$$(0,1)$$(1,1)$$(0,0)$$z$$|z|$$1 / z$$-z$$\bar{z}$$\bar{z}$$x$$y$$x y$$y$$z_{1}=3+2 i$$z_{2}=5+6 i$$z_{1}&gt;z_{2}$$z_{1}&lt;z_{2}$$\overline{z_{1}}=\overline{z_{2}}$$\overline{z_{1}}=-\overline{z_{2…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 18:55:54 +0000</pubDate>
        </item>
        <item>
            <title>Solutions: Math 11 NBF</title>
            <link>https://www.mathcity.org/math-11-nbf/sol</link>
            <description>Solutions: Math 11 NBF

[Solutions of Model Textbook of Mathematics for Class XI]
Solutions of Model Textbook of Mathematics for Class XI is published by National Book Foundation (NBF), Islamabad, Pakistan. NBF can be considered as Federal Textbook Board Islamabad. 
Federal Board of Intermediate and Secondary Education (FBISE), Islamabad has been introduced Students Learning Outcomes (SLOs) Based Examination. Its complete scheme of studies is available on the FBISE website</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 01 Feb 2025 19:18:00 +0000</pubDate>
        </item>
        <item>
            <title>Mechanics I (Statics) by Dr Babar Ahmad</title>
            <link>https://www.mathcity.org/notes/mechanics-i-statics-dr-babar-ahmad</link>
            <description>Mechanics I (Statics) by Dr Babar Ahmad

[Mechanics I (Statics) by Dr Babar Ahmad]

We are very thankful to Dr Babar Ahmad for sharing his book on MathCity.org. This book is very helpful for undergraduate students of Science and Engineering Programs. 

This book is shared by the permission of the author and he keeps the copyright of the book.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 24 Jul 2023 12:49:29 +0000</pubDate>
        </item>
        <item>
            <title>Unit 01: Complex Numbers (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01</link>
            <description>Unit 01: Complex Numbers (Solutions)

This is a first unit of the book Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. On this page we have provided the solutions of the questions.$z$$z^2+a^2$$z^3-3z^2+z=5$$pz^2+qz+r=0$$p,q,r$$z$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 27 Oct 2025 18:47:40 +0000</pubDate>
        </item>
        <item>
            <title>Unit 02: Matrices and Determinants (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02</link>
            <description>Unit 02: Matrices and Determinants (Solutions)

This is a second unit of the book Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. On this page we have provided the solutions of the questions.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 08 Feb 2026 17:04:31 +0000</pubDate>
        </item>
        <item>
            <title>Unit 04: Sequences and Seeries</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04</link>
            <description>Unit 04: Sequences and Seeries

This is a forth unit of the book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. On this page we have provided the solutions of the questions.$n$$n$$n$$n$$n$$n$$n$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 06 Oct 2024 17:46:06 +0000</pubDate>
        </item>
        <item>
            <title>Unit 05: Polynomials</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05</link>
            <description>Unit 05: Polynomials

[Unit 05: Polynomials]
This is a fifth unit of the book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. On this page we have provided the solutions of the questions.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 18:05:52 +0000</pubDate>
        </item>
        <item>
            <title>Unit 06: Permutation and Combination</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06</link>
            <description>Unit 06: Permutation and Combination

This is a sixth unit of the book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. On this page we have provided the solutions of the questions.$n$$n!$$n$$r$$n$$r$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 09 Mar 2025 10:56:17 +0000</pubDate>
        </item>
        <item>
            <title>Unit 08: Fundamental of Trigonometry</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08</link>
            <description>Unit 08: Fundamental of Trigonometry

[Unit 08: Fundamental of Trigonometry]
This is a eight unit of the book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. On this page we have provided the solutions of the questions.$\cos(\alpha -\beta)=\cos \alpha \cos\beta+\sin\alpha \sin\beta$$\cos(\alpha +\beta)=\cos \alpha \cos\beta-\sin\alpha \sin\beta$$\sin(\alpha \pm \beta)=\sin \alpha \cos\beta \pm \sin\alpha \co…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:51:30 +0000</pubDate>
        </item>
        <item>
            <title>Unit 09: Trigonometric Functions</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09</link>
            <description>Unit 09: Trigonometric Functions

This is a ninth unit of the book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. On this page we have provided the solutions of the questions.$a+b \sin \theta$$a+b \cos \theta$$a+b \sin(c \theta+d)$$a+b \cos(c \theta+d)$$a, b, c$$d$$\sin \theta$$\cos \theta$$\tan \theta$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:25 +0000</pubDate>
        </item>
        <item>
            <title>A-Course of Mathematics (Paper A &amp; B)</title>
            <link>https://www.mathcity.org/bsc/paper_pattern/sargodha_university/a-course_of_mathematics</link>
            <description>A-Course of Mathematics (Paper A &amp; B)
This subject is consists of two papers of 100 marks each. One is called “Paper A” and other is called “Paper B”. This page is updated on February 15, 2015. This syllabus is for 1st Annual 2015 and onward organized by University of Sargodha, Sargodha.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:55:54 +0000</pubDate>
        </item>
        <item>
            <title>General Mathematics (Paper A &amp; B)</title>
            <link>https://www.mathcity.org/bsc/paper_pattern/sargodha_university/general_mathematics</link>
            <description>General Mathematics (Paper A &amp; B)

This subject is consists of two papers of 100 marks each. One is called “Paper A” and other is called “Paper B”. This syllabus is for 1st Annual 2015 and onward organized by University of Sargodha (UoS), Sargodha.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:55:55 +0000</pubDate>
        </item>
        <item>
            <title>Pure Mathematics (Paper A &amp; B)</title>
            <link>https://www.mathcity.org/bsc/paper_pattern/sargodha_university/pure_mathematics</link>
            <description>Pure Mathematics (Paper A &amp; B)

This paper consist of two papers of 100 marks each. One paper is called “Paper A” and the other is called “Paper B”.

Paper A

	*  NOTE: attempt two questions from each section.

SECTION-I (4/12: 17,17,17,17)</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:55:59 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 1.1 (Solutions)</title>
            <link>https://www.mathcity.org/fsc-part1-ptb/sol/ch01/ex1-1</link>
            <description>Exercise 1.1 (Solutions)
Notes (Solutions) of Exercise 1.1: Textbook of Algebra and Trigonometry Class XI (Mathematics FSc Part 1 or HSSC-I), Punjab Textbook Board (PTB) Lahore.
The main topics of this exercise are properties of real numbers, binary operation, addition and multiplication law, properties of equality, properties of inequality (order properties), field, rule of fractions. These notes are based on the new Student Learning Outcomes (SLOs). Version: 4.0, Available at MathCity.org $\{0…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 13 Apr 2023 09:34:48 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 2.8 (Solutions)</title>
            <link>https://www.mathcity.org/fsc-part1-ptb/sol/ch02/ex2-8</link>
            <description>Exercise 2.8 (Solutions)
Notes (Solutions) of Exercise 2.8: Textbook of Algebra and Trigonometry Class XI (Mathematics FSc Part 1 or HSSC-I), Punjab Textbook Board (PTB) Lahore.
The main topic of this exercise are binary operation, semi-group, monoid, groups and abelian groups. These notes are based on the new Student Learning Outcomes (SLOs). Version: 4.1, Available at MathCity.org $\oplus$$G=\{0,1\}$\[
\begin{array}{|c|c|c|}
\hline
  \oplus &amp; 0 &amp; 1 \\ 
\hline
   0 &amp; 1 &amp; 1 \\
\hline
   1 &amp; 1 &amp; …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 05 Apr 2023 12:55:15 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 1.1 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-1</link>
            <description>Exercise 1.1 (Solutions)

The solutions of the Exercise 1.1 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to sum, product and division of the complex numbers.${{i}^{31}}$${{\left( -i \right)}^{6}}$${{\left( -1 \right)}^{\frac{-13}{2}}}$$\dfrac{2}{(-1)^{\frac{3}{2}}}$$i^{23}+i^{58}+i^{21}$$x+iy$$(3+2i)+(2+4i)$$(4+3i)-(2+5i)$$(4+7i…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 27 Oct 2025 18:50:29 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 1.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-1-p1</link>
            <description>Question 1, Exercise 1.1

Solutions of Question 1 of Exercise 1.1 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 1(i)
${{i}^{31}}$\begin{align}{{i}^{31}}&amp;=i\cdot{{i}^{30}}\\
&amp;=i\cdot{{\left( {{i}^{2}} \right)}^{15}}\\
&amp;=i\cdot{{\left( -1 \right)}^{15}} \quad \because i^2=-1\\
&amp;=i\cdot(-1)\\
&amp;=-i.\end{align}${{\left( -i \right)}^{6}}$\begin{align}
{{\left…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 09:40:00 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 1.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-1-p2</link>
            <description>Question 2, Exercise 1.1

Solutions of Question 2 of Exercise 1.1 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 2(i)
$x+iy$$(3+2i)+(2+4i)$\begin{align}&amp;(3+i2)+(2+i4)\\
=&amp;(3+2)+(i2+i4)\\
=&amp;5+i6\end{align}$x+iy$$(4+3i)-(2+5i)$\begin{align}&amp;(4+3i)-(2+5i)\\
=&amp;(4-2)+(3i-5i)\\
=&amp;2-2i\end{align}$x+iy$$(4+7i)+(4-7i)$\begin{align}
&amp;(4+7i)+(4-7i)\\
=&amp;(4+4)+(7i-7i…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:10:43 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 1.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-1-p3</link>
            <description>Question 3, Exercise 1.1

Solutions of Question 3 of Exercise 1.1 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 3(i)
$\dfrac{(2+i)(3-2i)}{1+i}$\begin{align}&amp;\dfrac{(2+i)(3-2i)}{1+i}\\
=&amp;\dfrac{6-2i^2+3i-4i}{1+i}\\
=&amp;\dfrac{8-i}{1+i}\\
=&amp;\dfrac{8-i}{1+i}\times \dfrac{1-i}{1-i}\\
=&amp;\dfrac{8+i^2-8i-i}{1^2-i^2}\\
=&amp;\dfrac{7-9i}{2}\\
=&amp;\dfrac{7}{2}-\dfrac{9}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:24:16 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 1.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-1-p4</link>
            <description>Question 4, Exercise 1.1

Solutions of Question 4 of Exercise 1.1 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 4(i)
$x$$y$$(2+3i)x+(1+3i)y+2=0$\begin{align}&amp;(2+3i)x+(1+3i)y+2=0\\
\implies &amp;(2x+y+2)+(3x+3y)i=0.\end{align}\begin{align}
2x+y+2&amp;=0 \quad \cdots(1)\\
3x+3y&amp;=0\quad \cdots (2)
\end{align}\begin{align}
&amp;3x=-3y \\
x=-y \quad ... (3) \end{align}$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:39:29 +0000</pubDate>
        </item>
        <item>
            <title>Question 5, Exercise 1.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-1-p5</link>
            <description>Question 5, Exercise 1.1

Solutions of Question 5 of Exercise 1.1 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 5
$z$$4z-3\bar{z}=\dfrac{1-18i}{2-i}$$z=x+iy$$\bar{z}=x-iy$\begin{align}&amp;4z-3\bar{z}=\dfrac{1-18i}{2-i}\\
\implies &amp;4(x+iy)-3(x-iy)=\dfrac{1-18i}{2-i}\times \dfrac{2+i}{2+i}\\
\implies &amp;4x+4iy-3x+3iy=\dfrac{(1-18i)(2+i)}{2^2-i^2} \end{align}\b…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 02 Jul 2024 16:57:50 +0000</pubDate>
        </item>
        <item>
            <title>Question 6, Exercise 1.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-1-p6</link>
            <description>Question 6, Exercise 1.1

Solutions of Question 6 of Exercise 1.1 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 6(i)
$4-3 i$$z=4-3 i$$\bar{z}=4+3i$$3 i+8$$2+\sqrt{\dfrac{-1}{5}}$\begin{align}z=&amp;2+\sqrt{\dfrac{-1}{5}}\\
=&amp;2+\sqrt{\dfrac{1}{5}}i,\end{align}$$\bar{z}=2-\sqrt{\dfrac{1}{5}}i$$$\dfrac{5 }{2}i-\dfrac{7}{8}$$z=\dfrac{5 }{2}i-\dfrac{7}{8},$$\bar…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:40:49 +0000</pubDate>
        </item>
        <item>
            <title>Question 7, Exercise 1.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-1-p7</link>
            <description>Question 7, Exercise 1.1

Solutions of Question 7 of Exercise 1.1 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 7(i)
$11+12 i$$$z=11+12i$$\begin{align}|z|&amp;= \sqrt{(11)^2+(12)^2}\\
&amp;=\sqrt{265}\end{align}$|11+12 i|=\sqrt{265}$$(2+3 i)-(2+6 i)$$z=(2+3i)−(2+6i)$\begin{align}z&amp;=2+3i−2−6i\\
&amp;=-3i \end{align}\begin{align}
|z| &amp;= \sqrt{0^2+(-3)^2} \\
&amp;= \sqrt{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 02 Jul 2024 16:57:27 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 1.2 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2</link>
            <description>Exercise 1.2 (Solutions)

The solutions of the Exercise 1.2 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to real and imaginary part of complex numbers, modulus and conjugate of the complex numbers.$\operatorname{Re}(i z)=-\operatorname{Im}(z)$$\operatorname{Im}(i z)=\operatorname{Re}(z)$$$\left(z_{1} z_{2}\right)\left(z_{3} z_{4…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 27 Oct 2025 18:50:09 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p1</link>
            <description>Question 1, Exercise 1.2

Solutions of Question 1 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 1(i)
$\operatorname{Re}(i z)=-\operatorname{Im}(z)$$$z=x+iy$$\begin{align}
iz&amp;=i(x+iy)\\
&amp;=ix-y\end{align}\begin{align}Re(iz)&amp;=-y\\
\implies Re(iz)&amp;=-Im(z)\end{align}$\operatorname{Im}(i z)=\operatorname{Re}(z)$$$z=x+iy$$\begin{align}iz&amp;=i(x+i…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:44:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p2</link>
            <description>Question 2, Exercise 1.2

Solutions of Question 2 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 2
$$
\left(z_{1} z_{2}\right)\left(z_{3} z_{4}\right)=\left(z_{1} z_{3}\right)\left(z_{2} z_{4}\right)=z_{3}\left(z_{1} z_{2}\right) z_{4}
$$\begin{align}
&amp;(z_1 z_2)(z_3 z_4) \\
=&amp;(z_1 z_2)z_5 \quad \text {Let }z_5=z_3 z_4 \\
=&amp;z_1 (z_2 z_5) \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:45:03 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p3</link>
            <description>Question 3, Exercise 1.2

Solutions of Question 3 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 3(i)
$z \in \mathbb{C}$$z$$z=\bar{z}$$$z=a+ib\quad \text{where}\quad a,b\in \mathbb{R}\, ... (1)$$$z$$\overline{z}=z$$z$$z$$b=0$\begin{align}
&amp;z=a \\
\implies &amp;\bar{z}=a \end{align}$z=\bar{z}$$\overline{z}=z$$z$\begin{align}&amp; z=\bar{z}\\
\Righ…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:53:00 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p4</link>
            <description>Question 4, Exercise 1.2

Solutions of Question 4 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 4
$z_{1}=2-3 i$$\left|z_{1} z_{2}\right|=16$$\left|z_{2}\right|$$$z_{1}=2-3i$$\begin{align}|z_1|&amp;=\sqrt{(2)^2+(-3)^2}\\
&amp;=\sqrt{13}\end{align}\begin{align}&amp;|z_{1} z_{2}|=16\\
\Rightarrow \quad &amp;|z_{1}|| z_{2}|=16\\
\Rightarrow \quad &amp; \sqrt{13…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:54:23 +0000</pubDate>
        </item>
        <item>
            <title>Question 5, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p5</link>
            <description>Question 5, Exercise 1.2

Solutions of Question 5 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 5
$z_1$$z_2$$|z_1+z_2|^2-|z_1-z_2|^2=4Re(z_1)Re(z_2)$\begin{align}z_1&amp;=x_1+iy_1 \text{ and } z_2&amp;=x_2+iy_2\end{align}\begin{align}z_1+z_2&amp;=x_1+iy_1+x_2+iy_2\\
 &amp;=x_1+x_2+i(y_1+y_2)\\
|z_1+z_2|^2&amp;=(x_1+x_2)^2+(y_1+y_2)^2\\
 &amp;=x^2_1+x^2_2+2x_1x_…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 12:55:01 +0000</pubDate>
        </item>
        <item>
            <title>Question 6, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p6</link>
            <description>Question 6, Exercise 1.2

Solutions of Question 6 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 6
$\lambda$$\left|\dfrac{z_{1}}{z_{2}}+\lambda\right|=\sqrt{\lambda+2}$$z_{1}=3+i$$z_{2}=1+i$\begin{align} &amp;z_{1}=3+i\text{ and } z_{2}=1+i.\end{align}\begin{align}
\dfrac{z_1}{z_2} &amp;= \dfrac{3+i}{1+i}\\
&amp;=\dfrac{(3+i)(1-i)}{(1+i)(1-i)} \\
&amp;=\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 13:16:48 +0000</pubDate>
        </item>
        <item>
            <title>Question 7, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p7</link>
            <description>Question 7, Exercise 1.2

Solutions of Question 7 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 7
$\sqrt{2}|z| \geq|\operatorname{Re}(z)|+|\operatorname{Im}(z)| \quad$$\left(|x|-|y|)^{2} \geq 0\right)$\begin{align}
&amp;\left(|x|-|y|)^{2} \geq 0\right) \\
\implies &amp; |x|^2+|y|^2-2|x||y| \geq 0 \\
\implies &amp; |x|^2+|y|^2 \geq 2|x||y| \\
\implie…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 13:32:58 +0000</pubDate>
        </item>
        <item>
            <title>Question 8, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p8</link>
            <description>Question 8, Exercise 1.2

Solutions of Question 8 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 8(i)
$|2 z-i|=4$$x$$y$$z=x+i y$$$|2z-i|=4.$$$z=x+i y$\begin{align}
&amp; |2(x+iy)-i|=4 \\
\implies &amp; |2x+i(2y-1)|=4 \\
\implies &amp; \sqrt{(2x)^2+(2y-1)^2}=4
\end{align}\begin{align}
&amp; (2x)^2+(2y-1)^2 = 16\\
\implies &amp; 4x^2+4y^2-4y+1-16=0 \\
\implies…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 10 Jul 2024 19:37:43 +0000</pubDate>
        </item>
        <item>
            <title>Question 9, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p9</link>
            <description>Question 9, Exercise 1.2

Solutions of Question 9 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 9(i)
$(2+4 i)^{-1}$$z=2+4i$\begin{align}
Re(2+4i)^{-1} &amp; = Re(z^{-1}) = \dfrac{Re(z)}{|z|^2} \\
&amp; =\dfrac{2}{2^2+4^2} = \dfrac{2}{20}\\ 
&amp;= \dfrac{1}{10}.
\end{align}\begin{align}
Im(2+4i)^{-1} &amp; = Im(z^{-1}) = -\dfrac{Im(z)}{|z|^2} \\
&amp; =-\df…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 19:38:59 +0000</pubDate>
        </item>
        <item>
            <title>Question 10, Exercise 1.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-2-p10</link>
            <description>Question 10, Exercise 1.2

Solutions of Question 10 of Exercise 1.2 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 10(i)
$z_{1}=-3+2 i$$$\left|z_{1}\right|=\left|-z_{1}\right|=\left|\overline{z_{!}}\right|=\left|-\overline{z_{!}}\right|.$$\begin{align}
|z_1| &amp;= \sqrt{(-3)^2 + (2)^2} \\ 
&amp;= \sqrt{9 + 4} = \sqrt{13} \,\, -- (1)
\end{align}\begin{align}
-z_…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Jul 2024 17:34:55 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 1.3 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-3</link>
            <description>Exercise 1.3 (Solutions)

The solutions of the Exercise 1.3 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to sum, product and division of the complex numbers.$z^{2}+169$$2 z^{2}+18$$3 z^{2}+363$$z^{2}+\dfrac{3}{25}$$2 z^{3}+3 z^{2}-10 z-15$$z^{3}-7 z+6$$z^{3}+2 z^{2}-23 z-60$$2 z^{3}+9 z^{2}-11 z-30$$z^{2}-7 z-8$$4 z^{2}-7 z-11$$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 27 Oct 2025 18:51:15 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 1.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-3-p1</link>
            <description>Question 1, Exercise 1.3

Solutions of Question 1 of Exercise 1.3 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 1(i)
$z^{2}+169$\begin{align} 
&amp; z^{2} + 169 \\
= &amp; z^{2} - (13i)^2 \\
= &amp;(z + 13i)(z - 13i).
\end{align}$2 z^{2}+18$\begin{align}
&amp; 2z^2 + 18 \\
= &amp;2(z^2 - (3i)^2)\\ 
= &amp;2(z + 3i)(z - 3i)
\end{align}$3 z^{2}+363$\begin{align}
&amp; 3z^2 + 363 \\ …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 14 Jul 2024 19:35:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 1.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-3-p2</link>
            <description>Question 2, Exercise 1.3

Solutions of Question 2 of Exercise 1.3 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 2(i)
$z^{2}-6 z+2=0$\begin{align} &amp; z^2 - 6z + 2 = 0 \\
\implies &amp; z^2 - 2(3)(z)+9-9+2=0 \\
\implies &amp; (z - 3)^2+7= 0 \\
\implies &amp;  (z - 3)^2 = 7.
\end{align}\begin{align} &amp;z - 3 = \pm \sqrt{7} \\
 \implies &amp;z = 3 \pm \sqrt{7}\end{align}$\{3 …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 14 Jul 2024 19:41:53 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 1.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-3-p3</link>
            <description>Question 3, Exercise 1.3

Solutions of Question 3 of Exercise 1.3 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 3(i)
$\dfrac{1}{3} z^{2}+2 z-16=0$\begin{align}&amp;\dfrac{1}{3}z^{2}+2 z-16=0\\
\implies &amp;z^{2} + 6z - 48 = 0 \end{align}$$ z = \dfrac{{-b \pm \sqrt{{b^2 - 4ac}}}}{2a},$$$$a = 1,\quad  b = 6,\quad \text{and}\quad  c = -48.$$\begin{align} 
z&amp; = \d…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 14 Jul 2024 19:45:23 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 1.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-3-p4</link>
            <description>Question 4, Exercise 1.3

Solutions of Question 4 of Exercise 1.3 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 4(i)
$(1-i) z+(1+i) \omega=3 ; 2 z-(2+5 i) \omega=2+3 i$\begin{align}
&amp;(1-i) z+(1+i) \omega=3 \quad \cdots(1)\\
&amp;2 z-(2+5 i) \omega=2+3i \quad\cdots(2)
\end{align}$2$\begin{align}
&amp;(2-2i)z+(2+2i) \omega=6  \quad \cdots (3)
\end{align}$(1-i)$\b…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 15 Jul 2024 12:19:22 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 1.4 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4</link>
            <description>Exercise 1.4 (Solutions)

The solutions of the Exercise 1.4 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to polar form of the complex numbers.$2+i 2 \sqrt{3}$$3-i \sqrt{3}$$-2-i 2$$\dfrac{i-1}{\cos \dfrac{\pi}{3}+i \sin \dfrac{\pi}{3}}$$\left(\cos \dfrac{\pi}{6}+i \sin \dfrac{\pi}{6}\right)\left(\cos \dfrac{\pi}{3}+i \sin \dfrac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 27 Oct 2025 18:51:55 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p1</link>
            <description>Question 1, Exercise 1.4

Solutions of Question 1 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 1(i)
$2+i 2 \sqrt{3}$$z=x+iy=2 + i 2 \sqrt{3}$\begin{align} 
r &amp; = \sqrt{x^2 + y^2} = \sqrt{2^2 + (2\sqrt{3})^2} \\
 &amp; = \sqrt{4 + 12} = \sqrt{16} = 4.
\end{align}\begin{align}
\alpha &amp; = \tan^{-1}\left|\frac{y}{x}\right| = \tan^{-1}\left|\fra…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 15 Jul 2024 12:24:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p2</link>
            <description>Question 2, Exercise 1.4

Solutions of Question 2 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 2(i)
$\left(\cos \dfrac{\pi}{6}+i \sin \dfrac{\pi}{6}\right)\left(\cos \dfrac{\pi}{3}+i \sin \dfrac{\pi}{3}\right)$$z_1=\cos \dfrac{\pi}{6}+i \sin \dfrac{\pi}{6}=e^{i\frac{\pi}{6}}$$z_2=\cos \dfrac{\pi}{3}+i \sin \dfrac{\pi}{3}=e^{i\frac{\pi}{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 05 Sep 2024 12:24:09 +0000</pubDate>
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        <item>
            <title>Question 3, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p3</link>
            <description>Question 3, Exercise 1.4

Solutions of Question 3 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 3(i)
$\left(x_{1}+i y_{1}\right)\left(x_{2}+i y_{2}\right)\left(x_{3}+i y_{3}\right) \ldots\left(x_{n}+i y_{n}\right)=a+i b$$\left(x_{1}^{2}+y_{1}^{2}\right)\left(x_{2}^{2}+y_{2}^{2}\right)\left(x_{3}^{2}+y_{3}^{2}\right) \ldots\left(x_{n}^{2}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 16:39:59 +0000</pubDate>
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        <item>
            <title>Question 4, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p4</link>
            <description>Question 4, Exercise 1.4

Solutions of Question 4 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 4
$\dfrac{1+z}{1-z}=\cos 2 \theta+i \sin 2 \theta$$z=i \tan \theta$\begin{align}&amp;\dfrac{1+z}{1-z}=\cos 2 \theta+i \sin 2 \theta\\
\implies &amp;\dfrac{1+z}{1-z}=e^{i2\theta}\\
\implies &amp;(1+z)=(1-z)e^{i2\theta}\\
\implies &amp;z+z e^{i2\theta}=e^{i2\th…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 15 Jul 2024 12:40:46 +0000</pubDate>
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        <item>
            <title>Question 5, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p5</link>
            <description>Question 5, Exercise 1.4

Solutions of Question 5 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 5
$\cos \alpha+\cos \beta+\cos \gamma=\sin \alpha+\sin \beta+\sin \gamma=0$$\cos 3 \alpha+\cos 3 \beta+\cos 3 \gamma=3 \cos (\alpha+\beta+\gamma)$$\sin 3 \alpha+\sin 3 \beta+\sin 3 \gamma=3 \sin (\alpha+\beta+\gamma)$\begin{align}
\cos \alpha …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 15 Jul 2024 12:41:11 +0000</pubDate>
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        <item>
            <title>Question 6(i-ix), Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p6</link>
            <description>Question 6(i-ix), Exercise 1.4

Solutions of Question 6(i-ix) of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sqrt{2}\left(\cos 315^{\circ}+i \sin 315^{\circ}\right)$\begin{align}
&amp;\sqrt{2}\left(\cos 315^{\circ}+i \sin 315^{\circ}\right) \\
=&amp; \sqrt{2} \left(\dfrac{1}{\sqrt{2}}-\dfrac{i}{\sqrt{2}} \right) \\
=&amp; 1-i.
\end{align}$5\left(\cos 210^{\ci…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:40:31 +0000</pubDate>
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        <item>
            <title>Question 6(x-xvii), Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p7</link>
            <description>Question 6(x-xvii), Exercise 1.4

Solutions of Question 6(x-xvii) of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $7 \sqrt{2}\left(\cos \dfrac{5 \pi}{4}+i \sin \dfrac{5 \pi}{4}\right)$$10 \sqrt{2}\left(\cos \dfrac{7 \pi}{4}+i \sin \dfrac{7 \pi}{4}\right)$$2\left(\cos\dfrac{5\pi}{2}+i \sin \dfrac{5\pi}{2}\right)$$\dfrac{1}{\sqrt{2}}\left(\cos \dfrac{\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:40:53 +0000</pubDate>
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        <item>
            <title>Question 7, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p8</link>
            <description>Question 7, Exercise 1.4

Solutions of Question 7 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 7(i)
$\arg (z-1)=-\dfrac{\pi}{4}$$z=x+iy$\begin{align*}
&amp;\arg (z-1)=-\dfrac{\pi}{4} \\
\implies &amp; \arg(x+iy-1) = -\dfrac{\pi}{4} \\
\implies &amp; \arg(x-1+iy) = -\dfrac{\pi}{4} \\
\implies &amp; \tan^{-1}\left(\dfrac{y}{x-1}\right) = -\dfrac{\pi}{4} …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:41:24 +0000</pubDate>
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        <item>
            <title>Question 8, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p9</link>
            <description>Question 8, Exercise 1.4

Solutions of Question 8 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 8(i)
$0.004 \mathrm{~mm}$$\dfrac{\pi}{4}$$$x_{\max}=0.004, \quad \theta=\dfrac{\pi}{4}.$$\begin{align}
x&amp;=x_{\max} e^{i\theta} \\
&amp;=0.004 e^{i\dfrac{\pi}{4}} \\
&amp;=\frac{4}{1000} \left(\cos\left(\dfrac{\pi}{4}\right) +i \sin\left(\dfrac{\pi}{4}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:41:56 +0000</pubDate>
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        <item>
            <title>Question 9, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p10</link>
            <description>Question 9, Exercise 1.4

Solutions of Question 9 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 9(i)
$x=2+3 i$$x_{\max }=1+4 i$$\mathrm{t}=0$$$x=2+3i$$$$x_{\max}=1+4 i$$$$\implies x=x_{\max} e^{i\theta}$$$$2+3i=(1+4 i) e^{i\theta}$$\begin{align}
\implies e^{i\theta}&amp;=\dfrac{2+3i}{1+4i} \\
&amp;=\dfrac{(2+3i)(1-4i)}{(1+4i)(1-4i)} \\
&amp;=\dfrac{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:46:32 +0000</pubDate>
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        <item>
            <title>Question 10, Exercise 1.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/ex1-4-p11</link>
            <description>Question 10, Exercise 1.4

Solutions of Question 10 of Exercise 1.4 of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 10(i)
$Z$$E=(-50+100 i)$$I=(-6-2 i)$$E=(-50+100 i)$$I=(-6-2 i)$$$ E = I \times Z $$$$(-50+100 i)= (-6-2 i) \times Z $$\begin{align}
\implies Z &amp; = \dfrac{-50+100 i}{-6-2 i} \\
&amp; = \dfrac{(-50+100 i)(-6+2i)}{(-6-2 i)(-6+2i)}\\
&amp; = \dfrac{300-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:47:07 +0000</pubDate>
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        <item>
            <title>Question 1, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/re-ex-p1</link>
            <description>Question 1, Review Exercise

Solutions of Question 1 of Review Exercise of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\operatorname{part}(\mathrm{s})$$z$$z$$(0,0)$$(1,0)$$(0,1)$$(1,1)$$(0,0)$$z$$|z|$$1 / z$$-z$$\bar{z}$$\bar{z}$$x$$y$$x y$$y$$z_{1}=3+2 i$$z_{2}=5+6 i$$z_{1}&gt;z_{2}$$z_{1}&lt;z_{2}$$\overline{z_{1}}=\overline{z_{2}}$$\overline{z_{1}}=-\overline{z_{2}}$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:53:04 +0000</pubDate>
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        <item>
            <title>Question 2, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/re-ex-p2</link>
            <description>Question 2, Review Exercise

Solutions of Question 2 of Review Exercise of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $i^{2}+i^{4}+i^{6}+\cdots+i^{100}$\begin{align*}
&amp; i^{2}+i^{4}+i^{6}+\ldots+i^{100} \\
=&amp; i^2 + (i^2)^2 + (i^2)^3 + (i^2)^4 + \ldots +(i^2)^{49} +(i^2)^{50} \\
=&amp; -1 + (-1)^2 + (-1)^3 + (-1)^4 + \ldots + (-1)^{49}+(-1)^{50} \\
=&amp; -1+1-1+1- \ldots -…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:53:23 +0000</pubDate>
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        <item>
            <title>Question 3, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/re-ex-p3</link>
            <description>Question 3, Review Exercise

Solutions of Question 3 of Review Exercise of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3 x^{2}+108$\begin{align*}
&amp; 3 x^{2}+108\\
=&amp;3 (x^{2}+36)\\
=&amp;3 (x^{2}-(6i)^2)\\
=&amp;3 (x+6i)(x-6i)
\end{align*}$4 x^{2}+40$\begin{align*}
&amp;4 x^{2}+40\\
=&amp;4 (x^{2}+10)\\
=&amp;4 (x^{2}+(\sqrt{10}i)^2)\\
=&amp;4 (x+\sqrt{10}i)(x-\sqrt{10}i)
\end{align*}</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:53:46 +0000</pubDate>
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        <item>
            <title>Question 4, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/re-ex-p4</link>
            <description>Question 4, Review Exercise

Solutions of Question 4 of Review Exercise of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $z=x+i y$$\left|\dfrac{z+2 i}{z-2 i}\right|=1$$z = x + iy$\begin{align*}
&amp; \left|\dfrac{z + 2i}{z - 2i}\right| = 1\\
\implies &amp; |z + 2i| = |z - 2i|\\
\implies &amp; |x + i(y + 2)| = |x + i(y - 2)|\\
\implies &amp;  \sqrt{x^2 + (y + 2)^2} = \sqrt{x^2 + (y -…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 12:54:02 +0000</pubDate>
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        <item>
            <title>Question 5, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/re-ex-p5</link>
            <description>Question 5, Review Exercise

Solutions of Question 5 of Review Exercise of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $z$$(z-3 i)(2+5 i)=3-4 i$$z$$(z-3 i)(2+5 i)=3-4 i$\begin{align*}
&amp;(z-3 i)(2+5 i)=3-4 i \\
\implies &amp; z-3 i=\dfrac{3-4 i}{2+5 i} \\
\implies &amp; z-3 i=\dfrac{(3-4 i)(2-5i)}{(2+5 i)(2-5i)}\\
\implies &amp; z-3 i=\dfrac{6-20-15i-8i}{4+25}\\
\implies &amp; z-3 i…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 16:47:30 +0000</pubDate>
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        <item>
            <title>Question 6, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/re-ex-p6</link>
            <description>Question 6, Review Exercise

Solutions of Question 6 of Review Exercise of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left[\dfrac{1}{i^{10}}+(2-i)^{2}+\sqrt{-25}\right]^{3}$\begin{align*}
&amp;\left[\dfrac{1}{i^{10}} + (2 - i)^2 + \sqrt{-25}\right]^3\\
=&amp;\left[\dfrac{1}{(i^2)^5} + ( 4 - 4i + i^2) + 5i \right]^3\\
=&amp;\left[\dfrac{1}{(-1)^5} + ( 4 - 4i -1) + 5i \right]…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 16:56:04 +0000</pubDate>
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        <item>
            <title>Question 7, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/re-ex-p7</link>
            <description>Question 7, Review Exercise

Solutions of Question 7 of Review Exercise of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 z^{2}-11 z+16=0$\begin{align*}
&amp;2 z^{2}-11 z+16=0\\
\implies&amp;z^2 - \dfrac{11}{2}z + 8 = 0\\
\implies&amp; z^2 - \dfrac{11}{2}z = -8\\
\implies&amp; z^2 - 2z\dfrac{11}{4}z + \dfrac{121}{16} = -8 + \dfrac{121}{16}\\
\implies&amp;\left(z-\dfrac{11}{4}\right)^2…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 16:59:42 +0000</pubDate>
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        <item>
            <title>Question 8, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/re-ex-p8</link>
            <description>Question 8, Review Exercise

Solutions of Question 8 of Review Exercise of Unit 01: Complex Numbers. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sqrt{2}+i \sqrt{2}$$\theta=45^{\circ}$$$x= \sqrt{2} + i \sqrt{2}, \quad \theta=\dfrac{\pi}{4}.$$$x_{\max}$\begin{align}
&amp;x=x_{\max} e^{i\theta} \\
\implies &amp; \sqrt{2} + i \sqrt{2}=x_{\max} e^{i\dfrac{\pi}{4}} \\
\implies &amp; x_{\max} \left(\cos\dfr…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 17 Jul 2024 17:13:41 +0000</pubDate>
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        <item>
            <title>Review Exercise 1 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit01/rev-ex</link>
            <description>Review Exercise 1 (Solutions)

The solutions of the Review Exercise 1 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to polar form of the complex numbers. $i^{2}+i^{4}+i^{6}+\cdots+i^{100}$$\left|\dfrac{(3-2 i)(1+i)}{2-3 i}\right|$$|\overline{(3-2 i)(4-i)}|$$\left(\dfrac{3+5 i}{2-3 i}\right)^{-1}$$3 x^{2}+108$$4 x^{2}+40$$z=x+i y$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 27 Oct 2025 18:52:39 +0000</pubDate>
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        <item>
            <title>Exercise 2.1 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-1</link>
            <description>Exercise 2.1 (Solutions)

The solutions of the Exercise 2.1 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to order, different type of matrices and transpose of matrix.$A=\left[\begin{array}{lll}1 &amp; 3 &amp; 0 \\ 2 &amp; 0 &amp; 1\end{array}\right]$$B=\left[\begin{array}{ll}1 &amp; 2 \\ 2 &amp; 3 \\ 3 &amp; 4\end{array}\right]$$C=\left[\begin{array}{l}1 \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 08 Feb 2026 16:35:15 +0000</pubDate>
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        <item>
            <title>Question 1, Exercise 2.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-1-p1</link>
            <description>Question 1, Exercise 2.1

Solutions of Question 1 of Exercise 2.1 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{lll}1 &amp; 3 &amp; 0 \\ 2 &amp; 0 &amp; 1\end{array}\right]$\begin{align}\text{Order of A}&amp;= 2\times 3\end{align}$B=\left[\begin{array}{ll}1 &amp; 2 \\ 2 &amp; 3 \\ 3 &amp; 4\end{array}\right]$\begin{align}\text{Order of B}&amp;= 3\times 2\end{align}$C…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 27 Jul 2024 09:35:52 +0000</pubDate>
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        <item>
            <title>Question 2, Exercise 2.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-1-p2</link>
            <description>Question 2, Exercise 2.1

Solutions of Question 2 of Exercise 2.1 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\quad A=\left[\begin{array}{lll}3 &amp; 6 &amp; 2 \\ 2 &amp; 1 &amp; 9\end{array}\right]$$B=\left[\begin{array}{ll}\frac{1}{3} &amp; 1 \\ 2 &amp; 6\end{array}\right]$$C=\left[\begin{array}{l}3 \\ 2 \\ 8\end{array}\right]$$D=\left[\begin{array}{lll}1 &amp; 6 &amp; 9 \\ 2 &amp; 0 …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 27 Jul 2024 09:36:13 +0000</pubDate>
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        <item>
            <title>Question 3, Exercise 2.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-1-p3</link>
            <description>Question 3, Exercise 2.1

Solutions of Question 3 of Exercise 2.1 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$A=\begin{bmatrix}
3 &amp; 0 &amp; 0 \\
0 &amp; 1 &amp; 0 \\
2 &amp; 6 &amp; 0
\end{bmatrix}$$$$B=\begin{bmatrix}
-6 &amp; 0 &amp; 0 \\
0 &amp; -6 &amp; 0 \\
0 &amp; 0 &amp; -6
\end{bmatrix}$$$$C=\begin{bmatrix}
1 &amp; 0 \\
2 &amp; 0
\end{bmatrix}$$$$D=\begin{bmatrix}
1 &amp; 0 &amp; 0 \\
0 &amp; 1 &amp; 0 \\
0 &amp;…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 27 Jul 2024 09:36:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 2.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-1-p4</link>
            <description>Question 4, Exercise 2.1

Solutions of Question 4 of Exercise 2.1 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$
A=\left[\begin{array}{ccc}
2 &amp; 0 \\
\sqrt{5} &amp; 6 \\
1 &amp; 9
\end{array}\right]$$$$
A^t=\begin{bmatrix}
2 &amp; \sqrt{5} &amp; 1 \\
0 &amp; 6 &amp; 9
\end{bmatrix}$$$$B=\left[\begin{array}{cccc}
1 &amp; 6 &amp; 2 &amp; 0
\end{array}\right] $$$$B^t=\left[\begin{array}{c}
1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 27 Jul 2024 09:36:55 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 2.2 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2</link>
            <description>Exercise 2.2 (Solutions)

The solutions of the Exercise 2.2 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to sum, product and different operations on matrices.$A=\left[a_{i j}\right]$$2 \times 2$$a_{i j}=\dfrac{i+3 j}{2}$$a_{i j}=\dfrac{i \times l}{2}$$a_{i j}=\dfrac{i}{j}$$a_{i j}=\dfrac{2 i-3 j}{3}$$B=\left[a_{\ell}\right]$$3 \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 08 Feb 2026 16:40:19 +0000</pubDate>
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        <item>
            <title>Question 1, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p1</link>
            <description>Question 1, Exercise 2.2

Solutions of Question 1 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[a_{i j}\right]$$2 \times 2$$a_{i j}=\dfrac{i+3 j}{2}$\( a_{ij} = \dfrac{i + 3j}{2} \)\( i = 1, j = 1 \)\[
a_{11} = \dfrac{1 + 3 \cdot 1}{2} = \dfrac{1 + 3}{2} = \dfrac{4}{2} = 2
\]\( i = 1, j = 2 \)\[
a_{12} = \dfrac{1 + 3 \cdot 2}{2} …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 30 Jul 2024 07:26:46 +0000</pubDate>
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        <item>
            <title>Question 3, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p2</link>
            <description>Question 3, Exercise 2.2

Solutions of Question 3 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{ccc}3 &amp; -1 &amp; 2 \\ 0 &amp; 6 &amp; 1 \\ -1 &amp; 0 &amp; -3\end{array}\right]$$B=\left[\begin{array}{ccc}2 &amp; 1 &amp; 7 \\ 0 &amp; 2 &amp; -1 \\ -3 &amp; 4 &amp; 2\end{array}\right]$$C$$A+B+C=0$$$A+B+C=0,$$$$C=-A-B.$$\begin{align*}
C&amp;=-\begin{bmatrix}3 &amp; -1 &amp;…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 30 Jul 2024 07:29:12 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p3</link>
            <description>Question 3, Exercise 2.2

Solutions of Question 3 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{ccc}3 &amp; -1 &amp; 2 \\ 0 &amp; 6 &amp; 1 \\ -1 &amp; 0 &amp; -3\end{array}\right]$$B=\left[\begin{array}{ccc}2 &amp; 1 &amp; 7 \\ 0 &amp; 2 &amp; -1 \\ -3 &amp; 4 &amp; 2\end{array}\right]$$C$$A+B+C=0$$$A+B+C=0,$$$$C=-A-B.$$\begin{align*}
C&amp;=-\begin{bmatrix}3 &amp; -1 &amp;…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 30 Jul 2024 07:30:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p4</link>
            <description>Question 4, Exercise 2.2

Solutions of Question 4 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A$\begin{align}\left[\begin{array}{cc} 2 &amp; 1 \\  3 &amp; 2 \end{array}\right]A\left[\begin{array}{cc} 1 &amp; 3 \\  2 &amp; 4 \end{array}\right]&amp;=\left[\begin{array}{cc} 1 &amp; 0 \\  0 &amp; 1 \end{array}\right]\end{align}$ B = \left[\begin{array}{cc} 2 &amp; 1 \\ 3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 30 Jul 2024 07:29:39 +0000</pubDate>
        </item>
        <item>
            <title>Question 5, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p5</link>
            <description>Question 5, Exercise 2.2

Solutions of Question 5 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $X=\left[\begin{array}{lll}1 &amp; 2 &amp; 2 \\ 2 &amp; 1 &amp; 2 \\ 2 &amp; 2 &amp; 1\end{array}\right]$$X^{2}-4 X-5 I=0$\begin{align}L.H.S. &amp; =X^{2}-4 X-5 I \\
&amp;=\begin{bmatrix}
1 &amp; 2 &amp; 2 \\
2 &amp; 1 &amp; 2 \\
2 &amp; 2 &amp; 1
\end{bmatrix}
\begin{bmatrix}
1 &amp; 2 &amp; 2 \\
2 &amp; 1 &amp; 2…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:11:12 +0000</pubDate>
        </item>
        <item>
            <title>Question 6, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p6</link>
            <description>Question 6, Exercise 2.2

Solutions of Question 6 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{cc}2 &amp; 1 \\ 3 &amp; -3\end{array}\right]$$\alpha$$\beta$$A^{2}+\alpha I=\beta A$\begin{align}
&amp; A^{2}+\alpha I=\beta A\\
\implies &amp;\begin{bmatrix}
2 &amp; 1 \\
3 &amp; -3
\end{bmatrix}
\begin{bmatrix}
2 &amp; 1 \\
3 &amp; -3
\end{bmatrix}+\a…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:24:24 +0000</pubDate>
        </item>
        <item>
            <title>Question 7, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p7</link>
            <description>Question 7, Exercise 2.2

Solutions of Question 7 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{ll}x &amp; 0 \\ y &amp; 1\end{array}\right]$$n, A^{n}=\left[\begin{array}{cc}x^{n} &amp; 0 \\ \dfrac{y\left(x^{n}-1\right)}{x-1} &amp; 1\end{array}\right]$$$A = \begin{bmatrix} x &amp; 0 \\ y &amp; 1 \end{bmatrix}.$$$n = 1$\begin{align}A^1 =\beg…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:42:50 +0000</pubDate>
        </item>
        <item>
            <title>Question 8, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p8</link>
            <description>Question 8, Exercise 2.2

Solutions of Question 8 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A$$B$$2 \times 3$$3 \times 2$$(A B)^{t}=B^{t} A^{t}$\( A \)\( B \)\( 2 \times 3 \)\( 3 \times 2 \)\begin{align*}
	A &amp;= \begin{bmatrix}
	a_{11} &amp; a_{12} &amp; a_{13} \\
	a_{21} &amp; a_{22} &amp; a_{23}
\end{bmatrix}\\
B &amp;= \begin{bmatrix}
	b_{11} &amp; b_{12}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:43:59 +0000</pubDate>
        </item>
        <item>
            <title>Question 9, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p9</link>
            <description>Question 9, Exercise 2.2

Solutions of Question 9 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A$$B$$3 \times 3$$(A+B)^{t}=A^{t}+B^{t}$\begin{align*}
A &amp;= \begin{pmatrix} 
a_{11} &amp; a_{12} &amp; a_{13} \\ 
a_{21} &amp; a_{22} &amp; a_{23} \\ 
a_{31} &amp; a_{32} &amp; a_{33} 
\end{pmatrix} \\
B &amp;= \begin{pmatrix} 
b_{11} &amp; b_{12} &amp; b_{13} \\ 
b_{21} &amp; b_{22…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:44:43 +0000</pubDate>
        </item>
        <item>
            <title>Question 10, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p10</link>
            <description>Question 10, Exercise 2.2

Solutions of Question 10 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A$$B$$A B=B$$B A=A$$A^{2}+B^{2}$$$AB = B$$$$BA = A$$\begin{align*}
A^2 &amp;= AA\\
&amp; = A(BA)\\
&amp;=(AB)A\\
&amp;=BA\\
&amp;=A
\end{align*}\begin{align*}
B^2&amp;= BB \\
&amp;=B(AB)\\
&amp; = (BA)B\\
&amp;=AB\\
&amp;=B\end{align*}$$A^2 + B^2 = A + B$$$AB = B$$BA = A$$$A^2 + B…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:47:00 +0000</pubDate>
        </item>
        <item>
            <title>Question 11, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p11</link>
            <description>Question 11, Exercise 2.2

Solutions of Question 11 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[a_{i j}\right]$$3 \times 3$$a_{i j}=i^{2}-j^{2}$$A$$A=\left[a_{i j}\right]$$a_{ij}=a+{ji}$$a_{ij}=-a_{ji}$$a_{i j}=i^{2}-j^{2}$\begin{align}
a_{ji} &amp; = j^2 -i^2 \\
&amp;= - (i^2 -j^2) \\
&amp;= - a_{ij}
\end{align}$a_{ij}=-a_{ji}$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:55:20 +0000</pubDate>
        </item>
        <item>
            <title>Question 12, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p12</link>
            <description>Question 12, Exercise 2.2

Solutions of Question 12 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A$$\left(A^{n}\right)^{t}=\left(A^{t}\right)^{n}$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:58:16 +0000</pubDate>
        </item>
        <item>
            <title>Question 13, Exercise 2.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p13</link>
            <description>Question 13, Exercise 2.2

Solutions of Question 13 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $X$$Y$$2 X-Y=\left[\begin{array}{ccc}1 &amp; 6 &amp; -3 \\ 2 &amp; 1 &amp; 7\end{array}\right]$$X+3 Y=\left[\begin{array}{ccc}4 &amp; 3 &amp; 2 \\ 1 &amp; -3 &amp; 0\end{array}\right]$\begin{align*}
2X - Y = \begin{pmatrix} 1 &amp; 6 &amp; -3 \\ 2 &amp; 1 &amp; 7 \end{pmatrix} \cdots (i)\\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 19 Aug 2024 16:58:35 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 2.3 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-3</link>
            <description>Exercise 2.3 (Solutions)

The solutions of the Exercise 2.3 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to determinant and inverse of the matrix.$\left[\begin{array}{ccc}2 &amp; 3 &amp; 1 \\ 1 &amp; -1 &amp; 2 \\ 4 &amp; 1 &amp; 2\end{array}\right]$$\left[\begin{array}{ccc}\cos \theta &amp; -\sin \theta &amp; 0 \\ \sin \theta &amp; \cos \theta &amp; 0 \\ 0 &amp; 0 &amp; 1\en…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 08 Feb 2026 16:44:16 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 2.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-3-p1</link>
            <description>Question 1, Exercise 2.3

Solutions of Question 1 of Exercise 2.3 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left[\begin{array}{ccc}2 &amp; 3 &amp; 1 \\ 1 &amp; -1 &amp; 2 \\ 4 &amp; 1 &amp; 2\end{array}\right]$\begin{align*}
A &amp;= \left[\begin{array}{ccc}2 &amp; 3 &amp; 1 \\ 1 &amp; -1 &amp; 2 \\ 4 &amp; 1 &amp; 2\end{array}\right]\\
|A|&amp;=2(-2-2)-3(2-8)+1(1+4)\\
\implies |A|&amp;=-8+18+5\\
\implies |…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 23 Aug 2024 09:03:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 2.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-3-p2</link>
            <description>Question 2, Exercise 2.3

Solutions of Question 2 of Exercise 2.3 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left[\begin{array}{lll}3 &amp; 2 &amp; 3 \\ 4 &amp; 5 &amp; 1 \\ 2 &amp; 1 &amp; 0\end{array}\right]$\(R_1\)\(a_{11} = 3\)\(a_{12} = 2\)\(a_{13} = 3\)\begin{align*}
A &amp;= \left[\begin{array}{ccc} 3 &amp; 2 &amp; 3 \\ 4 &amp; 5 &amp; 1 \\ 2 &amp; 1 &amp; 0 \end{array}\right]\\
&amp; A_{11} = (-1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 23 Aug 2024 09:04:07 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 2.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-3-p3</link>
            <description>Question 3, Exercise 2.3

Solutions of Question 3 of Exercise 2.3 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left[\begin{array}{ccc}3 &amp; 1 &amp; 2 \\ 2 &amp; 3 &amp; 1 \\ -4 &amp; 1 &amp; -3\end{array}\right]$\begin{align*}
A &amp;= \left[\begin{array}{ccc} 3 &amp; 1 &amp; 2 \\ 2 &amp; 3 &amp; 1 \\ -4 &amp; 1 &amp; -3\end{array}\right]\end{align*}\(3 \times 3\)\begin{align*}
|A| &amp;= 3(3 \cdot (-3) …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 23 Aug 2024 09:04:42 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 2.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-3-p4</link>
            <description>Question 4, Exercise 2.3

Solutions of Question 4 of Exercise 2.3 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\lambda$$\left[\begin{array}{lll}\lambda &amp; 1 &amp; 3 \\ 2 &amp; 1 &amp; 8 \\ 0 &amp; 3 &amp; 1\end{array}\right]$\begin{align*}
A &amp;= \left[\begin{array}{ccc}
\lambda &amp; 1 &amp; 3 \\
2 &amp; 1 &amp; 8 \\
0 &amp; 3 &amp; 1
\end{array}\right]\\
|A| &amp;= \lambda \cdot (-23) - 1 \cdot 2 + 3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 23 Aug 2024 09:05:13 +0000</pubDate>
        </item>
        <item>
            <title>Question 5, Exercise 2.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-3-p5</link>
            <description>Question 5, Exercise 2.3

Solutions of Question 5 of Exercise 2.3 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left[\begin{array}{ccc}1 &amp; -1 &amp; 1 \\ 2 &amp; 1 &amp; -1 \\ 1 &amp; -2 &amp; -1\end{array}\right]$\begin{align*}
A &amp;= \left[\begin{array}{ccc}
1 &amp; -1 &amp; 1 \\
2 &amp; 1 &amp; -1 \\
1 &amp; -2 &amp; -1
\end{array}\right]\\
|A|&amp;=  1 [-1 - 2] + 1 [-2 + 1] + 1 [-4 - 1] \\
&amp;= 1 \cd…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 23 Aug 2024 09:05:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 6, Exercise 2.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-3-p6</link>
            <description>Question 6, Exercise 2.3

Solutions of Question 6 of Exercise 2.3 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{ccc}2 &amp; 1 &amp; -3 \\ 0 &amp; 1 &amp; 0 \\ 2 &amp; 1 &amp; 6\end{array}\right]$$A^{-1}$$A A^{-1}=A^{-1} A=I_{3}$\begin{align*} A &amp;= \begin{bmatrix}
2 &amp; 1 &amp; -3 \\
0 &amp; 1 &amp; 0 \\
2 &amp; 1 &amp; 6
\end{bmatrix} \end{align*}$ A^{-1} $$ A $\begin{align*}
…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 23 Aug 2024 09:41:19 +0000</pubDate>
        </item>
        <item>
            <title>Question 7, Exercise 2.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-3-p7</link>
            <description>Question 7, Exercise 2.3

Solutions of Question 7 of Exercise 2.3 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $(A B)^{-1}=B^{-1} A^{-1}$$A=\left[\begin{array}{ll}2 &amp; 1 \\ 8 &amp; 6\end{array}\right]$$B=\left[\begin{array}{ll}3 &amp; 2 \\ 0 &amp; 2\end{array}\right]$\begin{align*}
A &amp;= \left[\begin{array}{ll}2 &amp; 1 \\ 8 &amp; 6\end{array}\right] \\	
|A|&amp; = 12 - 8 = 4\\	…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 23 Aug 2024 09:48:00 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 2.4 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-4</link>
            <description>Exercise 2.4 (Solutions)

The solutions of the Exercise 2.4 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to the determinant and properties of the determinant.$\left|\begin{array}{lll}9 &amp; 27 &amp; 36 \\ 18 &amp; 54 &amp; 24 \\ 27 &amp; 81 &amp; 28\end{array}\right|=0$$\left|\begin{array}{lll}1 / a &amp; b c &amp; b+c \\ 1 / b &amp; a c &amp; a+c \\ 1 / c &amp; a b &amp; a+…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 08 Feb 2026 16:46:40 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 2.5 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-5</link>
            <description>Exercise 2.5 (Solutions)

The solutions of the Exercise 2.5 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to solving system of the equation of three variables by using matrices.$\left[\begin{array}{ccc}1 &amp; 3 &amp; 5 \\ -6 &amp; 8 &amp; 3 \\ -4 &amp; 6 &amp; 5\end{array}\right]$$\left[\begin{array}{ll}2 &amp; 1 \\ 3 &amp; 2 \\ 1 &amp; 9\end{array}\right]$$\left[…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 08 Feb 2026 16:50:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 2.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-5-p1</link>
            <description>Question 1, Exercise 2.5

Solutions of Question 1 of Exercise 2.5 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left[\begin{array}{ccc}1 &amp; 3 &amp; 5 \\ -6 &amp; 8 &amp; 3 \\ -4 &amp; 6 &amp; 5\end{array}\right]$\begin{align*}
&amp; \quad \left[\begin{array}{ccc}1 &amp; 3 &amp; 5 \\ -6 &amp; 8 &amp; 3 \\ -4 &amp; 6 &amp; 5\end{array}\right]\\
\sim &amp; \text{R}
\left[\begin{array}{ccc}
1 &amp; 3 &amp; 5 \\
0 &amp; …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:01:24 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 2.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-5-p2</link>
            <description>Question 2, Exercise 2.5

Solutions of Question 2 of Exercise 2.5 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left[\begin{array}{ccc}5 &amp; 9 &amp; 3 \\ 3 &amp; -5 &amp; 6 \\ 2 &amp; 10 &amp; 6\end{array}\right]$\begin{align*}&amp;\quad\left[ \begin{array}{ccc}
5 &amp; 9 &amp; 3 \\ 
3 &amp; -5 &amp; 6 \\ 
2 &amp; 10 &amp; 6 
\end{array} \right]\\
\sim &amp; \text{R}\left[ \begin{array}{ccc}
1 &amp; \frac{9}{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:01:56 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 2.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-5-p3</link>
            <description>Question 3, Exercise 2.5

Solutions of Question 3 of Exercise 2.5 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left[\begin{array}{ccc}0 &amp; -1 &amp; -1 \\ -1 &amp; 3 &amp; 0 \\ 1 &amp; -1 &amp; 4\end{array}\right]$$A A^{-1}=A^{-1} A=I$\begin{align*}
A&amp;=\left[ \begin{array}{ccc}
0 &amp; -1 &amp; -1  \\ 
-1 &amp; 3 &amp; 0  \\ 
1 &amp; -1 &amp; 4 
\end{array} \right]\\
|A|&amp;=0+1(-4)-1(1-3)\\
&amp;=-4+3\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:02:35 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 2.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p1</link>
            <description>Question 1, Exercise 2.6

Solutions of Question 1 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $ 2 x_{1}-3 x_{2}+4 x_{3}=0$$x_{1}-2 x_{2}+3 x_{3}=0$$4 x_{1}+x_{2}-6 x_{3}=0$\begin{align*}
&amp;2 x_{1}-3 x_{2}+4 x_{3}=0\cdots (i)\\
&amp;x_{1}-2 x_{2}+3 x_{3}=0\cdots (ii)\\
&amp;4 x_{1}+x_{2}-6 x_{3}=0\cdots (iii)\\
\end{align*}\begin{align*}
A &amp;= \le…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:03:49 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 2.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p2</link>
            <description>Question 2, Exercise 2.6

Solutions of Question 2 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\lambda$$\lambda$$2 x_{1}-\lambda x_{2}+x_{3}=0$$2 x_{1}+3 x_{2}-x_{3}=0$$3 x_{1}-2 x_{2}+4 x_{3}=0$\begin{align*}
&amp;2 x_{1}-\lambda x_{2}+x_{3}=0 \cdots(i)\\
&amp;2 x_{1}+3 x_{2}-x_{3}=0\cdots(ii)\\
&amp;3 x_{1}-2 x_{2}+4 x_{3}=0\cdots(iii)\\
\end{ali…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:04:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 2.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p3</link>
            <description>Question 3, Exercise 2.6

Solutions of Question 3 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 x+3 y+4 z=2$$2 x+y+z=5$$3 x-2 y+z=-3$\begin{align*}
\begin{aligned}
2x + 3y + 4z &amp;= 2 \\
2x + y + z &amp;= 5 \\
3x - 2y + z &amp;= -3
\end{aligned}\end{align*}\begin{align*}
A_{b} &amp;=\quad \left[\begin{array}{cccc}
2 &amp; 3 &amp; 4 &amp; 2 \\
2 &amp; 1 &amp; 1 &amp; 5 \\
3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:11:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 2.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p4</link>
            <description>Question 4, Exercise 2.6

Solutions of Question 4 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 x_{1}-x_{2}-x_{3}=2$$3 x_{1}-4 x_{2}+3 x_{3}=7$$4 x_{1}+2 x_{2}-5 x_{3}=10$\begin{align*}
2x_1 - x_2 - x_3 &amp;= 2, \\
3x_1 - 4x_2 + 3x_3 &amp;= 7, \\
4x_1 + 2x_2 - 5x_3 &amp;= 10,
\end{align*}\begin{align*}	
A_b &amp;= \begin{bmatrix}
2 &amp; -1 &amp; -1 &amp; : &amp; 2 …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:11:42 +0000</pubDate>
        </item>
        <item>
            <title>Question 5, Exercise 2.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p5</link>
            <description>Question 5, Exercise 2.6

Solutions of Question 5 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $x_{1}+x_{2}+2 x_{3}=8$$-x_{1}-2 x_{2}+3 x_{3}=1$$3 x_{1}-7 x_{2}+4 x_{3}=10$$A X=B$\begin{align*}
&amp;A = \begin{bmatrix}
1 &amp; 1 &amp; 2 \\
-1 &amp; -2 &amp; 3 \\
3 &amp; -7 &amp; 4
\end{bmatrix}, \quad
X = \begin{bmatrix}
x_1 \\
x_2 \\
x_3
\end{bmatrix}, \quad
B = \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:12:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 6, Exercise 2.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p6</link>
            <description>Question 6, Exercise 2.6

Solutions of Question 6 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $5 x+3 y+z=6$$2 x+y+3 z=19$$x+2 y+4 z=25$\begin{align*}
A &amp;= \begin{bmatrix}
5 &amp; 3 &amp; 1 \\
2 &amp; 1 &amp; 3 \\
1 &amp; 2 &amp; 4
\end{bmatrix}, \quad
X = \begin{bmatrix}
x \\
y \\
z
\end{bmatrix}, \quad
B = \begin{bmatrix}
6 \\
19 \\
25
\end{bmatrix}
\end{alig…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:13:00 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8, Exercise 2.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p7</link>
            <description>Question 7 and 8, Exercise 2.6

Solutions of Question 7 and 8 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{ccc}3 &amp; 2 &amp; 1 \\ 4 &amp; -1 &amp; 2 \\ 7 &amp; 3 &amp; -3\end{array}\right]$$A^{-1}$$3 x+4 y+7 z=14 ; 2 x-y+3 z=4 ; \quad x+2 y-3 z=0$\begin{align*}
A &amp;= \begin{bmatrix}
3 &amp; 2 &amp; 1 \\
4 &amp; -1 &amp; 2 \\
7 &amp; 3 &amp; -3
\end{bmatrix}\\
|…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:13:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 and 10, Exercise 2.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p8</link>
            <description>Question 9 and 10, Exercise 2.6

Solutions of Question 9 and 10 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 x-y+3 z=\alpha ; 3 x+y-5 z=\beta ;-5 x-5 y+21 z=\gamma$$\gamma \neq 2 \alpha-3 \beta$$2$$2$$3$$3$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:13:56 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/re-ex-p1</link>
            <description>Question 1, Review Exercise

Solutions of Question 1 of Review Exercise of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A$$m \times n$$B$$n \times p$$A B$$n \times p$$m \times p$$p \times m$$n \times n$$m \times p$$A$$1 \times n$$A^{t} A$$1 \times n$$n \times 1$$1 \times 1$$n \times n$$n \times n$$a_{i j}$$A$$a_{i j}=(-1)^{i+j} A_{i j}$$a_{i j}=(-1)^{i+j}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 25 Nov 2024 17:51:01 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 and 3, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/re-ex-p2</link>
            <description>Question 2 and 3, Review Exercise

Solutions of Question 2 and 3 of Review Exercise of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{ccc}1 &amp; 2 &amp; 0 \\ -3 &amp; 4 &amp; 9 \\ 2 &amp; 1 &amp; 6\end{array}\right]$$A_{13}, A_{23}$$A_{33}$$|A|$\begin{align*}
A&amp;=\left[\begin{array}{ccc}1 &amp; 2 &amp; 0 \\ -3 &amp; 4 &amp; 9 \\ 2 &amp; 1 &amp; 6\end{array}\right]\\
A_{13} &amp;= (-1)^{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:15:23 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 and 5, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/re-ex-p3</link>
            <description>Question 4 and 5, Review Exercise

Solutions of Question 4 and 5 of Review Exercise of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left|\begin{array}{ccc}a+1 &amp; l &amp; l \\ l &amp; a+1 &amp; l \\ l &amp; l &amp; a+1\end{array}\right|=(a+1+2 l)(a+1-l)^{2}$\begin{align*}
L.H.S &amp;= \left|\begin{array}{ccc}a+1 &amp; l &amp; l \\ l &amp; a+1 &amp; l \\ l &amp; l &amp; a+1\end{array}\right|\\
&amp;=\left|\b…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 04 Sep 2024 03:15:45 +0000</pubDate>
        </item>
        <item>
            <title>Review Exercise 2 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit02/rev-ex</link>
            <description>Review Exercise 2 (Solutions)

The solutions of the Review Exercise 2 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the MCQs and question all topics included in this chapter.$A$$m \times n$$B$$n \times p$$A B$$n \times p$$m \times p$$p \times m$$n \times n$$A$$1 \times n$$A^{t} A$$1 \times n$$n \times 1$$1 \times 1$$n \times n$$a_{i j}$$A$$a_{i j}=(-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 08 Feb 2026 16:57:09 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p1</link>
            <description>Question 1 and 2, Exercise 4.1

Solutions of Question 1 and 2 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$a_{10}$$a_{15}$$$a_{n}=3 n+1$$$$a_{n}=3 n+1$$\begin{align*}
a_1 &amp;= 3(1) + 1 = 3 + 1 = 4\\
a_2 &amp;= 3(2) + 1 = 6 + 1 = 7\\
a_3 &amp;= 3(3) + 1 = 9 + 1 = 10\\
a_4 &amp;= 3(4) + 1 = 12 + 1 = 13\\
\end{align*}\begin{align*}
a_{10} &amp;= 3(10) + 1 = 30…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:29:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p2</link>
            <description>Question 3 and 4, Exercise 4.1

Solutions of Question 3 and 4 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$a_{10}$$a_{n}=\frac{n}{n+1}$$$a_n = \frac{n}{n+1}.$$\begin{align*}

a_1 &amp;= \frac{1}{1+1} = \frac{1}{2}\\
a_2 &amp;= \frac{2}{2+1} = \frac{2}{3}\\
a_3 &amp;= \frac{3}{3+1} = \frac{3}{4}\\
a_4 &amp;= \frac{4}{4+1} = \frac{4}{5}\\
\end{align*}\begin…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:33:03 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p3</link>
            <description>Question 5 and 6, Exercise 4.1

Solutions of Question 5 and 6 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$a_{10}$$a_{15}$$a_{n}=n^{2}-2 n$$$a_n = n^2 - 2n.$$\begin{align*}
a_1 &amp;= (1)^2 - 2(1) = 1 - 2 = -1\\
a_2 &amp;= (2)^2 - 2(2) = 4 - 4 = 0\\
a_3 &amp;= (3)^2 - 2(3) = 9 - 6 = 3\\
a_4 &amp;= (4)^2 - 2(4) = 16 - 8 = 8\\
\end{align*}\begin{align*}
a_{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:37:26 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p4</link>
            <description>Question 7 and 8, Exercise 4.1

Solutions of Question 7 and 8 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$a_{10}$$a_{15}$$a_{n}=\left(\frac{-1}{2}\right)^{n-1}$$$a_n = \left( \frac{-1}{2} \right)^{n-1}.$$\begin{align*}a_1 &amp;= \left( \frac{-1}{2} \right)^{1-1} = \left( \frac{-1}{2} \right)^0 = 1 \\
a_2 &amp;= \left( \frac{-1}{2} \right)^{2-1} =…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:39:31 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 and 10, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p5</link>
            <description>Question 9 and 10, Exercise 4.1

Solutions of Question 9 and 10 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$a_{10}$$a_{15}$$a_{n}=(-1)^{n}(n+3)$$n$$a_{10}$$a_{15}$$$a_{n}=(-1)^{n+1}(3 n-5).$$$$a_n = (-1)^{n+1}(3n - 5).$$\begin{align*}
a_1 &amp;= (-1)^{1+1}(3(1) - 5) = (1)(3 - 5) = -2 \\
a_2 &amp;= (-1)^{2+1}(3(2) - 5) = (-1)(6 - 5) = -1 \\
a_3 &amp;=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:42:36 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 and 12, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p6</link>
            <description>Question 11 and 12, Exercise 4.1

Solutions of Question 11 and 12 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{n}=4 n-3; a_8$$$a_n = 4n - 3.$$\begin{align*}
a_8 &amp;= 4(8) - 3 \\
&amp;= 32 - 3 \\
&amp;= 29
\end{align*}$a_8 = 29$$a_{n}=5 n+11 ; a_{9}$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:45:13 +0000</pubDate>
        </item>
        <item>
            <title>Question 13 and 14, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p7</link>
            <description>Question 13 and 14, Exercise 4.1

Solutions of Question 13 and 14 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{n}=(3 n+4)(2 n-5) ; a_{7}$$a_{n}=(-1)^{n-1}(3.4 n-17.3) ; a_{12}$$$a_n = (-1)^{n-1}(3.4n - 17.3).$$\begin{align*}
a_{12} &amp;= (-1)^{12-1}(3.4 \cdot 12 - 17.3) \\
&amp;= (-1)^{11}(40.8 - 17.3) \\
&amp;= (-1)^{11}(23.5) \\
&amp;= -23.5
\end{align…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:46:57 +0000</pubDate>
        </item>
        <item>
            <title>Question 15 and 16, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p8</link>
            <description>Question 15 and 16, Exercise 4.1

Solutions of Question 15 and 16 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{n}=4 n^{2}(11 n+31) ; a_{22}$$$a_n = 4n^2(11n + 31).$$\begin{align*}
a_{22} &amp;= 4 \cdot 22^2 \cdot (11 \cdot 22 + 31) \\
&amp;= 4 \cdot 484 \cdot (242 + 31) \\
&amp;= 4 \cdot 484 \cdot 273 \\
&amp;= 4 \cdot 132132 \\
&amp;= 528528
\end{align*}$a_{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:48:53 +0000</pubDate>
        </item>
        <item>
            <title>Question 17 and 18, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p9</link>
            <description>Question 17 and 18, Exercise 4.1

Solutions of Question 17 and 18 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{n}=\log 10^{n} ; a_{43}$$$a_n = \log 10^n.$$\begin{align*}
a_{43} &amp;= \log 10^{43} \\
&amp;= 43 \cdot \log 10 \\
&amp;= 43 \cdot 1 \\
&amp;= 43
\end{align*}$a_{43}= 43$$a_{n}=\ln e^{n} ; a_{67}$$$a_n = \ln e^n.$$\begin{align*}
a_{67} &amp;= \ln e^…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 17:38:01 +0000</pubDate>
        </item>
        <item>
            <title>Question 19 and 20, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p10</link>
            <description>Question 19 and 20, Exercise 4.1

Solutions of Question 19 and 20 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{n}$$1,3,5,7,9, \ldots$$$1, 3, 5, 7, 9, \ldots$$$a_1=1$$d=3-1=2$$$a_n = a_1 + (n - 1) d$$\begin{align*}
\implies a_n &amp;= 1 + (n - 1) \cdot 2\\
 &amp;= 1 + 2n - 2\\
&amp;= 2n - 1 \end{align*}$a_n = 2n - 1$$a_{n}$$3,9,27,81,243, \ldots$\begin…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 17:59:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 21 and 22, Exercise 4.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-1-p11</link>
            <description>Question 21 and 22, Exercise 4.1

Solutions of Question 21 and 22 of Exercise 4.1 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{n}$$\sqrt{2}, \sqrt{4}, \sqrt{6}, \sqrt{8}, \sqrt{10}, \ldots$$$\sqrt{2}, \sqrt{4}, \sqrt{6}, \sqrt{8}, \sqrt{10}, \ldots$$\begin{align*}
&amp;a_1=\sqrt{2 \cdot 1}, \\
&amp;a_2=\sqrt{4}=\sqrt{2 \cdot 2} \\
&amp;a_3=\sqrt{6}=\sqrt{2 \cdot 3}\\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 18:01:00 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p1</link>
            <description>Question 1, Exercise 4.2

Solutions of Question 1 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=4, d=3$$a_1= 4$$d=3$$$a_n = a_1 + (n - 1)d.$$\begin{align*}
a_2&amp;=4+(2-1)3=4+3=7\\
a_3 &amp;= 4+ (3-1) 3 = 4 + 6 = 10\\
a_4&amp;=4+(4-1)3=4+9=13
\end{align*}$a_1=4$$a_2=7$$a_3=10$$a_4=13$$a_1=7$$d=5$$a_1= 7$$d=5$$$a_n = a_1 + (n - 1)d.$$\begin{align*}
…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 15 Sep 2024 12:26:08 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p2</link>
            <description>Question 2, Exercise 4.2

Solutions of Question 2 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $5,9,13, \ldots$$$5, 9, 13, \ldots $$$a_1=5$$d=9-5=4$$$a_n=a_1+(n-1)d.$$\begin{align*}
a_4 &amp;=5+(4-1)(4)=5+12=17\\
a_5 &amp;=5+(5-1)(4)=5+16=21\\
a_6 &amp;=5+(6-1)(4)=5+20=25
\end{align*}$17$$21$$25$$11,14,17, \ldots$$$11, 14, 17, \ldots$$$a_1=11$$d=14-11=3$$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 15 Sep 2024 12:29:31 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p3</link>
            <description>Question 3 and 4, Exercise 4.2

Solutions of Question 3 and 4 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $0.07,0.12,0.7, \ldots$$$0.07,0.12,0.7, \ldots$$$a_1 = 0.07$$d=0.05$$a_{11}=?$\begin{align*}
a_n&amp;=a_1+(n-1)d \\
\implies a_{11}&amp;= 0.07+(11-1)(0.05)\\
&amp;=0.07+(10)(0.05)\\
&amp;=0.57
\end{align*}$a_{11}=0.57.$$a_3 = 14$$a_9 = -1$$$a_n = a_1 + (…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 20 Sep 2024 16:59:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p4</link>
            <description>Question 5 and 6, Exercise 4.2

Solutions of Question 5 and 6 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{17}=-40$$a_{28}=-73$$a_{1}$$d$$$a_n=a_1+(n-1)d$$\begin{align*}
&amp; a_{17} = -40 \\
\implies &amp;a_1 + 16d = -40 \quad \cdots (1)
\end{align*}\begin{align*}
&amp;a_{28}=-73\\
\implies &amp;a_1 + 27d = -73 \quad \cdots (2)
\end{align*}\begin{align*}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 20 Sep 2024 17:08:12 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p5</link>
            <description>Question 7 and 8, Exercise 4.2

Solutions of Question 7 and 8 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $-6,-2,2, \ldots$$70$$-6,-2,2, \ldots$$a_1=-6$$d=-2+6=4$$a_n=70$$n=?$$$a_n=a_1+(n-1)d.$$\begin{align*}
&amp;70=-6+(n-1)4\\
\implies &amp;70=-6+4n-4\\
\implies &amp;70=4n-10\\
\implies &amp;4n=80\\
\implies &amp; n=20
\end{align*}$a_{20}=70$$\dfrac{5}{2}, \df…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 20 Sep 2024 17:20:28 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 and 10, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p6</link>
            <description>Question 9 and 10, Exercise 4.2

Solutions of Question 9 and 10 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{1}{a}, b, \dfrac{1}{c}$$\dfrac{a-c}{2 a c}$$\dfrac{1}{a}, b, \dfrac{1}{c}$\begin{align*}
d&amp;=b-\frac{1}{a}\cdots (i)\\
\end{align*}\begin{align*}
d&amp;=\frac{1}{c}-b \cdots (ii)
\end{align*}\begin{align*}
b-\frac{1}{a}&amp;=\frac{1}{c}-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 20 Sep 2024 17:28:31 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 and 12, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p7</link>
            <description>Question 11 and 12, Exercise 4.2

Solutions of Question 11 and 12 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $1000$$3000$$2$$5000$$3$$20$$$1000, 3000, 5000, \dots, \text{ upto 20 terms}.$$$a_1 = 1000$$d=3000-1000=2000$$S_20=?$$$S_n =\frac{n}{2}[2a_1+(n-1)d],$$\begin{align*}
S_{20} &amp;= \frac{20}{2}[2(1000)+(20-1)2000]\\
&amp;= 10 [2000+(19)2000] \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 20 Sep 2024 17:46:01 +0000</pubDate>
        </item>
        <item>
            <title>Question 13, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p8</link>
            <description>Question 13, Exercise 4.2

Solutions of Question 13 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $7$$17$$a=7$$b=17$\begin{align*}
\text{A.M.} &amp;= \frac{a + b}{2}\\
&amp;= \frac{7 + 17}{2} \\
&amp;= \frac{24}{2} = 12.
\end{align*}$12$$3+3 \sqrt{2}$$7-3 \sqrt{2}$$a=3+3\sqrt{2}$$b=7-3\sqrt{2}$\begin{align*}
\text{A.M.} &amp;= \frac{a + b}{2}\\
&amp;= \frac{(3 + 3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 20 Sep 2024 18:05:05 +0000</pubDate>
        </item>
        <item>
            <title>Question 14 and 15, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p9</link>
            <description>Question 14 and 15, Exercise 4.2

Solutions of Question 14 and 15 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $b$$10$$b$$20$$a= b$$b=20$\begin{align*}
&amp;\text{A.M.} = \frac{a + b}{2} \\
\implies &amp; 10 = \frac{b + 20}{2} \\
\implies &amp; 20 = b + 20 \\
\implies &amp; b = 20 - 20 \\
\implies &amp; b = 0
\end{align*}$b = 0$$b$$25$$b$$20$$b$$10$$b$$-10$$x$$y$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 20 Sep 2024 18:31:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 16 and 17, Exercise 4.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-2-p10</link>
            <description>Question 16 and 17, Exercise 4.2

Solutions of Question 16 and 17 of Exercise 4.2 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $5$$17$$A_1$$A_2$$5$$17$$5$$A_1$$A_2$$17$$a_1=5$$a_4=17$$$a_n=a_1+(n-1)d.$$\begin{align*}
&amp;a_4 = a_1 + 3d \\
\implies &amp; 17=5+3d\\
\implies &amp; 3d=12\\
\implies &amp; \boxed{d=4}.\end{align*}\begin{align*}
A_1 &amp;= a_2= a_1+d \\
&amp;=5+4=9 \end{a…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 20 Sep 2024 18:45:04 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p1</link>
            <description>Question 1 and 2, Exercise 4.3

Solutions of Question 1 and 2 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $4+7+10+13+16+19+22+25$$4+7+10+13+16+19+22+25$$a_1=4$$d=7-4=3$$n=8$\begin{align}
S_n&amp;=\frac{n}{2}[2a_1+(n-1)d]\\
\implies S_8&amp;=\frac{8}{2}[2(4)+(8-1)(3)]\\
&amp;=4[8+7\times 3] = 116
\end{align}$a_{1}=2$$a_{n}=200$$n=100$$a_{1}=2$$a_{n}=200$$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:15:56 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p2</link>
            <description>Question 3 and 4, Exercise 4.3

Solutions of Question 3 and 4 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=5$$a_{n}=100$$n=200$$a_{1}=5$$a_{n}=100$$n=200$$a_{1}=5$$a_{n}=100$$n=200$$S_n$\begin{align}
S_n&amp;=\frac{n}{2}[a_1+a_n] \\
\implies S_{200}&amp;=\frac{200}{2}[5+100]\\
&amp;=10500.
\end{align}$S_{200}=10500$$a_{1}=4$$n=15$$d=3$$a_{1}=4$$n=1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:17:02 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p3</link>
            <description>Question 5 and 6, Exercise 4.3

Solutions of Question 5 and 6 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=50$$n=20$$d=-4$$a_{1}=50$$n=20$$d=-4$$a_{1}=50$$n=20$$d=-4$$S_n$\begin{align}
S_n&amp;=\frac{n}{2}[2a_1+(n-1)d] \\
\implies S_{20}&amp;=\frac{20}{2}[2(50)+(20-1)(-4)]\\
&amp;=10\times [100-76]\\
&amp;=240.
\end{align}$S_{20}=240$$-3+(-7)+(-11)+\cd…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:17:27 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p4</link>
            <description>Question 7 and 8, Exercise 4.3

Solutions of Question 7 and 8 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $9+11+13+15+\cdots$$n=12$$a_1=9$$d=11-9=2$$n=12$$S_n$\begin{align}
S_n&amp;=\frac{n}{2}[2a_1+(n-1)d] \\
\implies S_{12}&amp;=\frac{12}{2}[2(9)+(12-1)(2)]\\
&amp;=6\times [18+22]\\
&amp;=240.
\end{align}$S_{12}=240$$2$$100$$2$$100$$$2+4+6+...+100 (50 \tex…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:17:56 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 and 10, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p5</link>
            <description>Question 9 and 10, Exercise 4.3

Solutions of Question 9 and 10 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $1$$99$$1$$99$$$1+3+5+...+99 (50 \text{ terms}).$$$a_{1}=1$$n=50$$d=3-1=2$$S_n$\begin{align}
S_n&amp;=\frac{n}{2}[2a_1+(n-1)d] \\
\implies S_{50}&amp;=\frac{50}{2}[2(1)+(50-1)(2)]\\
&amp;=25\times [2+98]\\
&amp;=2500.
\end{align}$1$$99$$2500$$14$$523$$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:19:25 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 and 12, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p6</link>
            <description>Question 11 and 12, Exercise 4.3

Solutions of Question 11 and 12 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $S_{\boldsymbol{n}}$$a_{1}=3$$a_{n}=-38$$n=8$$a_{1}=3$$a_{n}=-38$$n=8$\begin{align}
S_n&amp;=\frac{n}{2}[a_1+a_n] \\
\implies S_{8}&amp;=\frac{8}{2}[3-38]\\
&amp;=4\times[-35] \\
&amp;=-140.
\end{align}$S_{8}=-140$$S_n$$a_{1}=85$$n=21$$a_{n}=25$$a_{1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:19:47 +0000</pubDate>
        </item>
        <item>
            <title>Question 13 and 14, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p7</link>
            <description>Question 13 and 14, Exercise 4.3

Solutions of Question 13 and 14 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $S_s$$a_{1}=34$$n=9$$a_{n}=2$$a_{1}=34$$n=9$$a_{n}=2$\begin{align}
S_n&amp;=\frac{n}{2}[a_1+a_n] \\
\implies S_{9}&amp;=\frac{9}{2}[34+2]\\
&amp;=162.
\end{align}$S_{9}=162$$S_n$$a_{1}=5$$d=\frac{1}{2}$$n=13$$a_{1}=5$$d=\frac{1}{2}$$n=13$\begin{a…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:23:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 15 and 16, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p8</link>
            <description>Question 15 and 16, Exercise 4.3

Solutions of Question 15 and 16 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $S_n$$a_{1}=91$$d=-4$$a_{n}=15$$a_{1}=91$$d=-4$$a_{n}=15$$n=?$\begin{align} 
&amp; a_n=a_1+(n-1)d \\
\implies &amp; 15=91+(n-1)(-4) \\
\implies &amp; 15=91-4n+4 \\
\implies &amp; 4n=95-15 \\
\implies &amp;  4n = 80\\ \implies &amp; n = 20.
\end{align}\begin{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:23:39 +0000</pubDate>
        </item>
        <item>
            <title>Question 17, 18 and 19, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p9</link>
            <description>Question 17, 18 and 19, Exercise 4.3

Solutions of Question 17, 18 and 19 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $6+12+18+\ldots+96$$$6+12+18+\ldots+96.$$$a_{1}=6$$d=12-6=6$$a_{n}=96$$n=?$\begin{align} 
&amp; a_n=a_1+(n-1)d \\
\implies &amp; 96=6+(n-1)(6) \\
\implies &amp; 96=6+6n-6 \\
\implies &amp; 6n=96 \\
\implies &amp;  n = 24.
\end{align}\begin{align}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:23:56 +0000</pubDate>
        </item>
        <item>
            <title>Question 20, 21 and 22, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p10</link>
            <description>Question 20, 21 and 22, Exercise 4.3

Solutions of Question 20, 21 and 22 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=7$$a_{n}=139$$S_{n}=876$$a_{1}=7$$a_{n}=139$$S_{n}=876$$n$$d$\begin{align}
&amp;S_n=\frac{n}{2}[a_1+a_n]\\
\implies &amp; 876=\frac{n}{2}[7+139]\\
\implies &amp; 1752=146n\\
\implies &amp; n=\frac{1752}{146}=12.
\end{align}\begin{align…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:24:21 +0000</pubDate>
        </item>
        <item>
            <title>Question 23 and 24, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p11</link>
            <description>Question 23 and 24, Exercise 4.3

Solutions of Question 23 and 24 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$ 14+16+18+...+a_{25}.$$$a_1=14$$d=16-14=2$$n=25$$a_25$$S_25$\begin{align}
a_n&amp;=a_1+(n-1)d\\
\implies a_{25}&amp;= 14+(25-1)(2)\\
&amp;=62.
\end{align}\begin{align}
S_n&amp;=\frac{n}{2}[a_1+a_n]\\
\implies S_{25}&amp; =\frac{25}{2}[14+62]\\
&amp; =25 \t…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:24:52 +0000</pubDate>
        </item>
        <item>
            <title>Question 25 and 26, Exercise 4.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-3-p12</link>
            <description>Question 25 and 26, Exercise 4.3

Solutions of Question 25 and 26 of Exercise 4.3 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$ 6000+70,000+...+a_{20}.$$$a_1=6,000$$d=70,000-6,000=64,000$$n=20$$S_n$\begin{align}
S_n&amp;=\frac{n}{2}[2a_1+(n-1)d]\\
\implies S_{20}&amp; =\frac{20}{2}[2(6,000)+(20-1)(64,000)]\\
&amp; =10 \times [12,000+1,216,000]\\
&amp; =12,280,000.
\end{ali…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 14 Sep 2024 16:25:19 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p1</link>
            <description>Question 1 and 2, Exercise 4.4

Solutions of Question 1 and 2 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $5,20,100,500, \ldots$$5, 20, 100, 500, \ldots $\begin{align*}
\frac{20}{5} = 4\neq \frac{100}{20} = 5.\end{align*}$5, 20, 100, 500, \ldots $\begin{align*}
r_1&amp; =\frac{20}{5} = 4\\
r_2&amp;=\frac{100}{20} = 5\\
r_3&amp;=\frac{500}{100} = 5.
\end{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:03 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p2</link>
            <description>Question 3 and 4, Exercise 4.4

Solutions of Question 3 and 4 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\frac{3}{2}, \frac{9}{4}, \frac{27}{8}, \frac{81}{16}, \ldots$\(\frac{3}{2}, \frac{9}{4}, \frac{27}{8}, \frac{81}{16}, \ldots\)\begin{align*}
r_1&amp;=\frac{9/4}{3/2} = \frac{9}{4} \times \frac{2}{3} = \frac{3}{2} \\
r_2&amp;=\frac{27/8}{9/4} = …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:06 +0000</pubDate>
        </item>
        <item>
            <title>Question 5, 6 and 7, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p3</link>
            <description>Question 5, 6 and 7, Exercise 4.4

Solutions of Question 5, 6 and 7 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=3, r=-2$$a_{1}=3$$r=-2$$$a_{n}=a_{1} r^{n-1}.$$\begin{align*}
&amp; a_{2}=a_{1} r=(3)(-2)= -6 \\
&amp; a_{3}=a_{1} r^{2}=(3)(-2)^{2}=3 (4)= 12 \\
&amp; a_{4}=a_{1} r^{3}=(3)(-2)^{3}=3  (-8) = -24
\end{align*}$a_1=3$$a_2=-6$$a_3=12$$a_4=-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:06 +0000</pubDate>
        </item>
        <item>
            <title>Question 8 and 9, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p4</link>
            <description>Question 8 and 9, Exercise 4.4

Solutions of Question 8 and 9 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$90,30,10 \ldots$$$a_1=90$$r=\dfrac{30}{90}=\dfrac{1}{3}$$$a_{n}=a_{1} r^{n-1}.$$\begin{align*}
&amp; a_{4}=a_{1} r^3=(90)\left(\dfrac{1}{3} \right)^3=90 \times\dfrac{1}{27}=\dfrac{10}{3}\\
&amp; a_{5}=a_{1} r^3=(90)\left(\dfrac{1}{4} \right)^4=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:06 +0000</pubDate>
        </item>
        <item>
            <title>Question 10 and 11, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p5</link>
            <description>Question 10 and 11, Exercise 4.4

Solutions of Question 10 and 11 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$20,30,45 \ldots$$\(a_1=20\)\(r=\frac{30}{20}=\frac{3}{2}\)$$a_{n}=a_{1} r^{n-1}.$$\begin{align*}
&amp; a_{4}=a_{1} r^3=(20)\left(\frac{3}{2}\right)^3=20 \times \frac{27}{8} = \frac{540}{8} = 67.5 \\ 
&amp; a_{5}=a_{1} r^4=(20)\left(\frac{3}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:07 +0000</pubDate>
        </item>
        <item>
            <title>Question 12 and 13, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p6</link>
            <description>Question 12 and 13, Exercise 4.4

Solutions of Question 12 and 13 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$\frac{1}{27}, \frac{1}{9}, \frac{1}{3}, \ldots$$\(a_1=\frac{1}{27}\)\(r=\frac{\frac{1}{9}}{\frac{1}{27}}=3\)$a_{n}=a_{1} r^{n-1}.$\begin{align*}
&amp; a_{4}=a_{1} r^3=\left(\frac{1}{27}\right)(3)^3=\frac{1}{27} \times 27 = 1 \\ 
&amp; a_{5}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:07 +0000</pubDate>
        </item>
        <item>
            <title>Question 14 and 15, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p7</link>
            <description>Question 14 and 15, Exercise 4.4

Solutions of Question 14 and 15 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=4, n=3, r=5$$a_{1}=4, n=3, r=5$$$a_{n}=a_{1} r^{n-1}.$$\begin{align*}
a_3&amp;= 4\times 5^2 \\
&amp;=4\times 25 = 100. 
\end{align*}$a_3=100$$a_{1}=2, n=5, r=2$$a_{1}=2$$n=5$$r=2$$a_{n}=a_{1} r^{n-1}.$\begin{align*}
a_5 &amp;= 2 \times 2^{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:08 +0000</pubDate>
        </item>
        <item>
            <title>Question 16 and 17, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p8</link>
            <description>Question 16 and 17, Exercise 4.4

Solutions of Question 16 and 17 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=7, n=4, r=2$$a_{1}=7$$n=4$$r=2$$a_{n}=a_{1} r^{n-1}.$\begin{align*}
a_4 &amp;= 7 \times 2^{4-1} \\ 
&amp;= 7 \times 2^3 \\ 
&amp;= 7 \times 8 = 56.
\end{align*}$a_4=56$$a_{1}=243, n=5, r=-\frac{1}{3}$$a_{1}=243$$n=5$$r=-\frac{1}{3}$$a_{n}=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:08 +0000</pubDate>
        </item>
        <item>
            <title>Question 18 and 19, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p9</link>
            <description>Question 18 and 19, Exercise 4.4

Solutions of Question 18 and 19 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=32, n=6, r=-\frac{1}{2}$$a_{1}=32$$n=6$$r=-\frac{1}{2}$$a_{n}=a_{1} r^{n-1}.$\begin{align*}
a_6 &amp;= 32 \times \left(-\frac{1}{2}\right)^{6-1} \\ 
&amp;= 32 \times \left(-\frac{1}{2}\right)^{5} \\ 
&amp;= 32 \times \left(-\frac{1}{32}\ri…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:09 +0000</pubDate>
        </item>
        <item>
            <title>Question 20 and 21, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p10</link>
            <description>Question 20 and 21, Exercise 4.4

Solutions of Question 20 and 21 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$3 , \_\_\_ , \_\_\_ , \_\_\_ , 48$$$a_1=3$$a_5=48$$r$$$
a_n=ar^{n-1}.
$$\begin{align*}
&amp;a_5=a_1 r^4 \\
\implies &amp; 48=3r^4 \\
\implies &amp; r^4 = 16 \\
\implies &amp; r^4 = 2^4 \\
\implies &amp; r = 2.
\end{align*}\begin{align*}
&amp; a_2=a_1 r= (3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:02 +0000</pubDate>
        </item>
        <item>
            <title>Question 22 and 23, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p11</link>
            <description>Question 22 and 23, Exercise 4.4

Solutions of Question 22 and 23 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$8 , \_\_\_, \_\_\_, \_\_\_, \_\_\_, \dfrac{1}{4}$$$a_1=8$$a_6=\frac{1}{4}$$r$$n$$a_n = a_1 r^{n-1}.$\begin{align*}
a_6 &amp;= a_1 r^5 \\
\implies \frac{1}{4} &amp;= 8 \cdot r^5 \\
\implies r^5 &amp;= \frac{1}{4 \cdot 8} \\
\implies r^5 &amp;= \frac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:03 +0000</pubDate>
        </item>
        <item>
            <title>Question 24 and 25, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p12</link>
            <description>Question 24 and 25, Exercise 4.4

Solutions of Question 24 and 25 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$5 , \_\_\_, \_\_\_, \_\_\_, 80$$$a_1=5$$a_5=80$$r$$n$$$a_n = a_1 r^{n-1}.$$\begin{align*}
a_5 &amp;= a_1 r^4 \\
\implies 80 &amp;= 5 \cdot r^4 \\
\implies r^4 &amp;= \frac{80}{5} \\
\implies r^4 &amp;= 16 \\
\implies r &amp;= 2.
\end{align*}\begin{alig…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:04 +0000</pubDate>
        </item>
        <item>
            <title>Question 26 and 27, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p13</link>
            <description>Question 26 and 27, Exercise 4.4

Solutions of Question 26 and 27 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $16\,\, ft$$6$$16\,\,ft$$a_1$$a_2$$a_3,...$$$a_1 = 16\times \dfrac{1}{4} = 4\,\, ft.$$$r=\dfrac{1}{4}$$a_6$$$a_{n}=a_{1} r^{n-1}.$$\begin{align*}
a_{6}&amp;=a_{1} r^5 \\
&amp;=(4)\left(\dfrac{1}{4} \right)^5 \\
&amp; = \dfrac{1}{256}
\end{align*}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:04 +0000</pubDate>
        </item>
        <item>
            <title>Question 28 and 29, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p14</link>
            <description>Question 28 and 29, Exercise 4.4

Solutions of Question 28 and 29 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $=a_1= 1$$= a_2 = 2$$= a_3 = 2(2)=4$$= a_7$$$
1+2+4+...+a_7
$$$a_1=1$$r=2$$n=7$$$
S_n=\frac{a_1\left(1-r^n \right)}{1-r}, \quad r\neq 1.
$$\begin{align*}
S_6&amp;=\frac{(1)\left(1-2^7 \right)}{1-2} \\
&amp;=\frac{1-128}{-2}\\
&amp;=127
\end{align…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:05 +0000</pubDate>
        </item>
        <item>
            <title>Question 30, Exercise 4.4</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-4-p15</link>
            <description>Question 30, Exercise 4.4

Solutions of Question 30 of Exercise 4.4 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $=a_1= 1$$=a_2= 3$$=a_3=3\times 3 = 9$$=a_4=3\times 9 = 27$$=a_5=3\times 27 = 81$$81$$a_1=1$$r=3$$a_5=?$$$a_n=a_1 r^{n-1}.$$\begin{align*}
a_5&amp;=a_1 r^4 \\
&amp;=(1)(3)^4 = 81
\end{align*}$$S_n=a_1+a_2+a_3+a_4+a_5.$$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:05 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p1</link>
            <description>Question 1 and 2, Exercise 4.5

Solutions of Question 1 and 2 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $16+16+16+\ldots$$a_1=16$$r=\dfrac{16}{16}=1$$r\neq 1$\begin{align*}
&amp;16+16+16+\ldots \text{ to 11 terms}\\
=&amp;11(16) \\
=&amp; 176
\end{align*}$75+15+3+...$$75+15+3+...$$a_1= 75$$r = \frac{15}{75} = \frac{1}{5}$$n = 10$$n$$$ S_n = \frac{a_1 \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:34:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p2</link>
            <description>Question 3 and 4, Exercise 4.5

Solutions of Question 3 and 4 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=5$$r=3$$n=12$$a_{1}=5$$r=3$$n=12$$n$\[
S_n = \frac{a_1 \left(1 - r^n\right)}{1 - r}, \quad r\neq 1.
\]\begin{align*}
S_{12} &amp;= \frac{5\left(1 - 3^{12}\right)}{1 - 3} \\
&amp;= \frac{5\left(1 - 531441\right)}{-2} \\
&amp;= \frac{5(-531440)}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p3</link>
            <description>Question 5 and 6, Exercise 4.5

Solutions of Question 5 and 6 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=7, r=2, n=14$$a_1 = 7$$r = 2$$n = 14$$n$$$S_n = \frac{a_1 \left(1 - r^n\right)}{1 - r}, \quad r \neq 1.$$\begin{align*}
S_{14} &amp;= \frac{7 \left(1 - 2^{14}\right)}{1 - 2} \\
&amp;= \frac{7 \left(1 - 16384\right)}{-1} \\
&amp;= \frac{7 \time…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p4</link>
            <description>Question 7 and 8, Exercise 4.5

Solutions of Question 7 and 8 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=16, r=-\frac{1}{2}, n=10$$a_1 = 16$$r = -\frac{1}{2}$$n = 10$$n$$$S_n = \frac{a_1 \left(1 - r^n\right)}{1 - r}, \quad r \neq 1.$$\begin{align*}
S_{10} &amp;= \frac{16 \left(1 - \left(-\frac{1}{2}\right)^{10}\right)}{1 - \left(-\frac{1}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:11 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 and 10, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p5</link>
            <description>Question 9 and 10, Exercise 4.5

Solutions of Question 9 and 10 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}=343, a_{4}=-1, r=-\frac{1}{7}$$a_{1}=343$$a_{4}=-1$$r=-\frac{1}{7}$$S_n$$$ S_n =\frac{a_1-a_n r}{1-r}, \quad r\neq 1.$$\begin{align*}
S_4 &amp; =\frac{343-(-1)\left(-\frac{1}{7}\right)}{1+\frac{1}{7}} \\
&amp;=\frac{\frac{2400}{7}}{\frac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:11 +0000</pubDate>
        </item>
        <item>
            <title>Question 11, 12 and 13, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p6</link>
            <description>Question 11, 12 and 13, Exercise 4.5

Solutions of Question 11, 12 and 13 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $a_{1}$$S_{n}=244, r=-3, n=5$$S_{n}=244$$r=-3$$n=5$$$ S_n =\frac{a_1(1-r^n)}{1-r}, \quad r\neq 1.$$\begin{align*}
&amp; 244=\frac{a_1(1-(-3)^5)}{1-(-3)} \\
\implies &amp; 244=\frac{a_1(1+243)}{4} \\
\implies &amp; 976=244a_1\\
\implies &amp; …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:12 +0000</pubDate>
        </item>
        <item>
            <title>Question 14, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p7</link>
            <description>Question 14, Exercise 4.5

Solutions of Question 14 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $0.444...$$$0.444... = 0.4+0.04+0.004+...$$$a_1=0.4$$r=\frac{0.04}{0.4}=0.1$$|r|=0.1 &lt; 1$\begin{align*}
S-\infty &amp; = \frac{a_1}{1-r} \\
&amp; = \frac{0.4}{1.0.1} = \frac{0.4}{0.9} \\
&amp; = \frac{4}{9}.
\end{align*}$S_{\infty} =\dfrac{4}{9}$$9.99999 ...$$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:12 +0000</pubDate>
        </item>
        <item>
            <title>Question 15, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p8</link>
            <description>Question 15, Exercise 4.5

Solutions of Question 15 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $30 ft$$\frac{2}{5}$$= 30 ft$$= 30 \times \frac{2}{5} = 12 ft$$= 12 \times \frac{2}{5} = \frac{24}{5} ft$$= \frac{24}{5} \times \frac{2}{5} = \frac{48}{25} ft$$D$$$D=30+2\left(12+\frac{24}{5}+\frac{24}{5}+... \right)$$$$
12+\frac{24}{5}+\frac{24}{5…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:26:13 +0000</pubDate>
        </item>
        <item>
            <title>Question 16, Exercise 4.5</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-5-p9</link>
            <description>Question 16, Exercise 4.5

Solutions of Question 16 of Exercise 4.5 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $80 ft$$90\%$$a_1$$a_1 r$$a_1 r^2$$=a_1= 80 ft$$r=90% = \frac{90}{100} =0.9$$A$\begin{align}
A &amp;= a_1+a_1r+a_1r^2+... \\
&amp; = \frac{a_1}{1-r} \\
&amp; = \frac{80}{1-0.9}\\
&amp;= 800
\end{align}$800 ft$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 22 Sep 2024 18:42:06 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2, Exercise 4.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-6-p1</link>
            <description>Question 1 and 2, Exercise 4.6

Solutions of Question 1 and 2 of Exercise 4.6 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\frac{1}{9}, \frac{1}{12}, \frac{1}{15}, \cdots \quad 7$$$\frac{1}{9}, \frac{1}{12}, \frac{1}{15}, \cdots \text{ is in H.P.}$$$$9, 12, 15, ... \text{ is in A.P.}$$$a_1=9$$d=12-9=3$$a_7=?$$$
a_n=a_1+(n-1)d.
$$\begin{align*}
a_7&amp;=9+(6)(3) …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 24 Sep 2024 18:04:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 &amp; 4, Exercise 4.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-6-p2</link>
            <description>Question 3 &amp; 4, Exercise 4.6

Solutions of Question 3 &amp; 4 of Exercise 4.6 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\frac{1}{18}, \frac{1}{13}, \frac{1}{8}, \ldots \quad 20$\begin{align*}
&amp;\frac{1}{18}, \frac{1}{13}, \frac{1}{8}, \ldots \quad \text{ is in H.P.} \\
&amp;18, 13, 8, \ldots \quad \text{ is in A.P.}
\end{align*}$a_1 = 18$$d = 13 - 18 = -5$$a_{20}.…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 24 Sep 2024 18:04:55 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 &amp; 6, Exercise 4.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-6-p3</link>
            <description>Question 5 &amp; 6, Exercise 4.6

Solutions of Question 5 &amp; 6 of Exercise 4.6 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{1}{27}, \dfrac{1}{20}, \dfrac{1}{13}, \ldots \quad$\begin{align*}
&amp;\frac{1}{27}, \frac{1}{20}, \frac{1}{13}, \ldots \quad \text{ is in H.P.} \\
&amp;27, 20, 13, \ldots \quad \text{ is in A.P.}
\end{align*}$a_1 = 27$$d = 20 - 27 = -7$$a_n=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 24 Sep 2024 18:08:03 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 &amp; 8, Exercise 4.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-6-p4</link>
            <description>Question 7 &amp; 8, Exercise 4.6

Solutions of Question 7 &amp; 8 of Exercise 4.6 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\frac{1}{4}, \frac{1}{7}, \frac{1}{10}, \frac{1}{13}, \ldots$$ \frac{1}{4}, \frac{1}{7}, \frac{1}{10}, \frac{1}{13}, \ldots $$ a_1 = \frac{1}{4} $$d = \frac{1}{7} - \frac{1}{4} = -\frac{3}{28},$$ n = 14$$$a_n = a_1 + (n-1)d.$$\begin{align*}
…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 24 Sep 2024 18:07:44 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 &amp; 10, Exercise 4.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-6-p5</link>
            <description>Question 9 &amp; 10, Exercise 4.6

Solutions of Question 9 &amp; 10 of Exercise 4.6 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\frac{1}{7}, \frac{1}{6},-1,-\frac{1}{3}, \ldots$$$\frac{1}{7}, \frac{1}{6}, -1, -\frac{1}{3}, \ldots \text{ is in H.P.}$$$$7, 6, -1, -3, \ldots \text{ is in A.P.}$$$a_1 = 7$$d = 6 - 7 = -1$$a_8=?$$$
a_n = a_1 + (n-1)d.
$$\begin{align*}
a_…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 24 Sep 2024 18:08:26 +0000</pubDate>
        </item>
        <item>
            <title>Question 11, Exercise 4.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-6-p6</link>
            <description>Question 11, Exercise 4.6

Solutions of Question 11 of Exercise 4.6 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{2}{3}$$\dfrac{4}{7}$$a=\dfrac{2}{3}$$b=\dfrac{4}{7}$\begin{align*}
\text{H.M.}&amp;=\frac{2ab}{a+b} \\
&amp;=\frac{2\times\frac{2}{3}\times\frac{4}{7}}{\frac{2}{3}+\frac{4}{7}} \\
&amp;=\frac{16/21}{26/21} \\
&amp;=\frac{8}{13} \\
\end{align*}$\dfrac{8}{13…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 24 Sep 2024 18:09:11 +0000</pubDate>
        </item>
        <item>
            <title>Question 12, Exercise 4.6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-6-p7</link>
            <description>Question 12, Exercise 4.6

Solutions of Question 12 of Exercise 4.6 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{1}{3}$$\dfrac{1}{11}$$H_1, H_2, H_3, H_4$$H.Ms$$\dfrac{1}{3}$$\dfrac{1}{11}$$$\dfrac{1}{3},H_1, H_2, H_3, H_4, \dfrac{1}{11} \text{ are in H.P.}$$$$\quad 3,\dfrac{1}{H_1},\dfrac{1}{H_2}, \dfrac{1}{H_3}, \dfrac{1}{H_4},11 \text{ are in A.P.}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 24 Sep 2024 18:09:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p1</link>
            <description>Question 1 and 2, Exercise 4.7

Solutions of Question 1 and 2 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sum_{k=1}^{5} \frac{1}{2 k}$\begin{align*}
\sum_{k=1}^{5} \frac{1}{2k} &amp;= \frac{1}{2(1)} + \frac{1}{2(2)} + \frac{1}{2(3)} + \frac{1}{2(4)} + \frac{1}{2(5)}\\
&amp;= \frac{1}{2} + \frac{1}{4} + \frac{1}{6} + \frac{1}{8} + \frac{1}{10}\\
&amp;= …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p2</link>
            <description>Question 3 and 4, Exercise 4.7

Solutions of Question 3 and 4 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sum_{k=0}^{5} 2^{k}$\begin{align*}
\sum_{k=0}^{5} 2^{k} &amp;= 2^0 + 2^1 + 2^2 + 2^3 + 2^4 + 2^5 \\
&amp;= 1 + 2 + 4 + 8 + 16 + 32 \\
&amp;= 63
\end{align*}$\sum_{k=0}^{9} \pi k$\begin{align*}
\sum_{k=0}^{9} \pi k &amp;= \pi(0) + \pi(1) + \pi(2) + \pi(…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p3</link>
            <description>Question 5 and 6, Exercise 4.7

Solutions of Question 5 and 6 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sum_{k=1}^{8} \frac{k}{k+1}$\begin{align*}
\sum_{k=1}^{8} \frac{k}{k+1} &amp;= \frac{1}{2} + \frac{2}{3} + \frac{3}{4} + \frac{4}{5} + \frac{5}{6}\\
&amp;+ \frac{6}{7} + \frac{7}{8} + \frac{8}{9} \\
&amp;= 0.5 + 0.6667 + 0.75 + 0.8 + 0.8333\\
&amp;+ 0.…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:39 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p4</link>
            <description>Question 7 and 8, Exercise 4.7

Solutions of Question 7 and 8 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sum_{k=0}^{5}\left(k^{2}-2 k+3\right)$\begin{align*}
\sum_{k=0}^{5} (k^{2} - 2k + 3) &amp;= (0^{2} - 2(0) + 3) + (1^{2} - 2(1) + 3) + (2^{2} - 2 (2) + 3) \\
&amp;+ (3^{2} - 2 (3) + 3) + (4^{2} - 2 (4) + 3) + (5^{2} - 2 (5) + 3) \\
&amp;= (0 - 0 + 3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:39 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 and 10, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p5</link>
            <description>Question 9 and 10, Exercise 4.7

Solutions of Question 9 and 10 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\frac{1}{2}+\frac{2}{3}+\frac{3}{4}+\frac{4}{5}+\frac{5}{6}+\dots$$$
\frac{1}{2} + \frac{2}{3} + \frac{3}{4} + \frac{4}{5} + \frac{5}{6} +... = \sum_{k=1}^{\infty}\frac{k}{k+1}
$$$3+6+9+12+15$$$3+6+9+12+15=\sum_{k=1}^{5}3k$$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 11, 12 and 13, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p6</link>
            <description>Question 11, 12 and 13, Exercise 4.7

Solutions of Question 11, 12 and 13 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $-2+4-8+16-32+64$$$
-2 + 4 - 8 + 16 - 32 + 64 = \sum_{k=1}^{6} (-1)^k 2^k
$$$\frac{1}{1 \cdot 2}+\frac{1}{2 \cdot 3}+\frac{1}{3 \cdot 4}+\frac{1}{4 \cdot 5}+$$$
\frac{1}{1 \cdot 2} + \frac{1}{2 \cdot 3} + \frac{1}{3 \cdot 4} +…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 14, 15 and 16, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p7</link>
            <description>Question 14, 15 and 16, Exercise 4.7

Solutions of Question 14, 15 and 16 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$n$$n+1$$T_n$$n$$$
T_{n} = n+1.
$$\begin{align*}\sum_{n=1}^{\infty} T_{n} &amp;= \sum_{n=1}^{\infty} (n+1)\\
&amp; = \sum_{n=1}^{\infty} n + \sum_{n=1}^{\infty} 1 \\
&amp; = \frac{n(n+1)}{2} + n \\
&amp; = \frac{n(n+1)}{2} + \frac{2n}{2} \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:41 +0000</pubDate>
        </item>
        <item>
            <title>Question 17 and 18, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p8</link>
            <description>Question 17 and 18, Exercise 4.7

Solutions of Question 17 and 18 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$2^{2}+5^{2}+8^{2}+\ldots$$2+5+8+\ldots$$a_k=2+(k-1)(3)=2+3k-3=3k-1$$T_k$$k$\begin{align*}T_k&amp;=(3k-1)^2 \\
&amp;=9k^2-6k+1. \end{align*}\begin{align*}\sum_{k=1}^{n} T_{k} &amp;= \sum_{k=1}^{n} (9k^{2} - 6k + 1)\\
&amp; = 9\sum_{k=1}^{n} k^{2} …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:41 +0000</pubDate>
        </item>
        <item>
            <title>Question 19 and 20, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p9</link>
            <description>Question 19 and 20, Exercise 4.7

Solutions of Question 19 and 20 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$1^{3}+3^{3}+5^{3}+$$1+3+5+\ldots$$a_k=1+(k-1)(2)=1+2k-2=2k-1$$T_k$$k$\begin{align*}T_k&amp;=(2k-1)^3 \\
&amp;=(2k)^3+3(2k)^2(-1)+3(2k)(-1)^2+(-1)^3 \\
&amp;=8k^3-12k^2+6k+1
\end{align*}\begin{align*}\sum_{k=1}^{n} T_{k} &amp;= \sum_{k=1}^{n} (8k^…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:43 +0000</pubDate>
        </item>
        <item>
            <title>Question 19 and 20, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p10</link>
            <description>Question 19 and 20, Exercise 4.7

Solutions of Question 19 and 20 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$1^{3}+3^{3}+5^{3}+$$1+3+5+\ldots$$a_k=1+(k-1)(2)=1+2k-2=2k-1$$T_k$$k$\begin{align*}T_k&amp;=(2k-1) \\
&amp;=9k^2-6k+1. \end{align*}\begin{align*}\sum_{k=1}^{n} T_{k} &amp;= \sum_{k=1}^{n} (2k - 1)\\
&amp; = 2 \sum_{k=1}^{n} k - \sum_{k=1}^{n} 1 \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 21 and 22, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p11</link>
            <description>Question 21 and 22, Exercise 4.7

Solutions of Question 21 and 22 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$1 \times 4+2 \times 7+3 \times 10+\cdots$$4+7+10+\ldots$$a_k=4+(k-1)(3)=4+3k-3=3k+1$$1+2+3+...$$k$$k(3k+1)$$T_k$$k$\begin{align*}T_k&amp;=k(3k+1) \\
&amp;=3k^2+k. \end{align*}\begin{align*}\sum_{k=1}^{n} T_{k} &amp;= \sum_{k=1}^{n} (3k^2 +k)\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 23 and 24, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p12</link>
            <description>Question 23 and 24, Exercise 4.7

Solutions of Question 23 and 24 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$$1+2 \times 2+3 \times 2^{2}+4 \times 2^{3}+\ldots.$$$$1+2 \times 2+3 \times 2^{2}+4 \times 2^{3}+\ldots$$$$
1\times 1+2 \times 2+3 \times 2^{2}+4 \times 2^{3}+\ldots
$$$1,2,3,4,\ldots$$a=1$$d=1$$1, 2, 2^2, 2^3, \ldots$$r=\frac{2}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 25 and 26, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p13</link>
            <description>Question 25 and 26, Exercise 4.7

Solutions of Question 25 and 26 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$1+\frac{4}{7}+\frac{7}{7^{2}}+\frac{10}{7^{3}}+\ldots$\[
1 + \frac{4}{7} + \frac{7}{7^2} + \frac{10}{7^3} + \ldots
\]\(1, 4, 7, 10, \ldots\)\(a = 1\)\(d = 3\)\(1, \frac{1}{7}, \frac{1}{7^2}, \frac{1}{7^3}, \ldots\)\(1\)\(r = \frac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:36 +0000</pubDate>
        </item>
        <item>
            <title>Question 27 and 28, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p14</link>
            <description>Question 27 and 28, Exercise 4.7

Solutions of Question 27 and 28 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$5+\frac{7}{3}+\frac{9}{9}+\frac{11}{27}+\ldots$$$$5+\frac{7}{3}+\frac{9}{9}+\frac{11}{27}+\ldots$$$$
5\times 1+7\times\frac{1}{3}+9\times\frac{1}{9}+11\times\frac{1}{27}+\ldots
$$$5,7,9,11,4,\ldots$$a=5$$d=7-5=2$$1, \dfrac{1}{3}, \d…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:36 +0000</pubDate>
        </item>
        <item>
            <title>Question 29 and 30, Exercise 4.7</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-7-p15</link>
            <description>Question 29 and 30, Exercise 4.7

Solutions of Question 29 and 30 of Exercise 4.7 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$1+4 x+7 x^{2}+10 x^{3}+\ldots$$\[
1 + 4x + 7x^2 + 10x^3 + \ldots
\]\[
1 \times 1 + 4 \times x + 7 \times x^2 + 10 \times x^3 + \ldots
\]\(1, 4, 7, 10, \ldots\)\(a = 1\)\(d = 4 - 1 = 3\)\(1, x, x^2, x^3, \ldots\)\(1\)\(r = x\)\[
S_{\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Fri, 04 Oct 2024 19:06:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2, Exercise 4.8</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-8-p1</link>
            <description>Question 1 and 2, Exercise 4.8

Solutions of Question 1 and 2 of Exercise 4.8 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3+7+13+21+\ldots$$n$$$ S_{n}=3+7+13+21+31+\ldots +T_{n} $$$$ S_{n}=3+7+13+21+\ldots +T_{n-1}+T_{n}.$$\begin{align*}
S_{n}-S_{n}&amp; =3+7+13+21+31+\ldots +T_{n}  \\
&amp; -\left(3+7+13+21+\ldots +T_{n-1}+T_{n}\right)
\end{align*}\begin{align*}
\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 06 Oct 2024 17:46:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 4.8</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-8-p2</link>
            <description>Question 3 and 4, Exercise 4.8

Solutions of Question 3 and 4 of Exercise 4.8 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $1+4+13+40+121+ \ldots$$n$$$ S_{n}=1+4+13+40+121+\ldots +T_{n} $$$$ S_{n}=1+4+13+40+\ldots +T_{n-1}+T_{n}. $$\begin{align*}
	S_{n}-S_{n}&amp; =1+4+13+40+121+\ldots +T_{n}  \\
	&amp; -\left(1+4+13+40+\ldots +T_{n-1}+T_{n}\right)
\end{align*}\begin…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 06 Oct 2024 17:46:48 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Exercise 4.8</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-8-p3</link>
            <description>Question 5 and 6, Exercise 4.8

Solutions of Question 5 and 6 of Exercise 4.8 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3+4+6+10+18+34+66+\dots$$n$$$ S_{n}=3+4+6+10+18+\ldots +T_{n} $$$$ S_{n}=3+4+6+10+\ldots +T_{n-1}+T_{n}. $$\begin{align*}
S_{n}-S_{n}&amp; =3+4+6+10+18+\ldots +T_{n}  \\
&amp; -\left(3+4+6+10+\ldots +T_{n-1}+T_{n}\right)
\end{align*}\begin{align…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 06 Oct 2024 17:47:09 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8, Exercise 4.8</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-8-p4</link>
            <description>Question 7 and 8, Exercise 4.8

Solutions of Question 7 and 8 of Exercise 4.8 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$$\frac{1}{1 \times 4}+\frac{1}{4 \times 7}+\frac{1}{7 \times 10}+\ldots$$$$\frac{1}{1 \times 4}+\frac{1}{4 \times 7}+\frac{1}{7 \times 10}+\dots$$$T_k$\begin{align*}
T_k &amp;=\frac{1}{(3k-2)(3k+1)}.
\end{align*}\begin{align*}
\frac{1}{(3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 06 Oct 2024 17:47:35 +0000</pubDate>
        </item>
        <item>
            <title>Question 9 and 10, Exercise 4.8</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-8-p5</link>
            <description>Question 9 and 10, Exercise 4.8

Solutions of Question 9 and 10 of Exercise 4.8 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$\frac{1}{1 \cdot 3}+\frac{1}{2 \cdot 5}+\frac{1}{3 \cdot 7}+\ldots \ldots \text{ up to } \infty$$$\sum_{k=3}^{n} \dfrac{1}{(k+1)(k+2)}$\begin{align*}
T_k &amp;= \frac{1}{(k+1)(k+2)}.
\end{align*}\begin{align*}
\frac{1}{(k+1)(k+2)} = \frac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 06 Oct 2024 17:48:05 +0000</pubDate>
        </item>
        <item>
            <title>Question 11 and 12, Exercise 4.8</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-8-p6</link>
            <description>Question 11 and 12, Exercise 4.8

Solutions of Question 11 and 12 of Exercise 4.8 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sum_{k=1}^{n} \frac{1}{k(k+2)}$$T_k$$k$\begin{align*}
T_k &amp;= \frac{1}{k(k+2)}.
\end{align*}\begin{align*}
\frac{1}{k(k+2)} = \frac{A}{k} + \frac{B}{k+2} \ldots (1)
\end{align*}$k(k+2)$\begin{align*}
	1 = A(k+2) + Bk \ldots (2)
\end{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 06 Oct 2024 17:48:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 13, 14 and 15, Exercise 4.8</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit04/ex4-8-p7</link>
            <description>Question 13, 14 and 15, Exercise 4.8

Solutions of Question 13, 14 and 15 of Exercise 4.8 of Unit 04: Sequence and Series. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\frac{1}{5 \cdot 11}+\frac{1}{7 \cdot 13}+\frac{1}{9 \cdot 15}+\ldots \ldots$$n$$T_k$$k$\begin{align*}
T_k &amp;= \frac{1}{(2k+3)(2k+9)}.
\end{align*}\begin{align*}
\frac{1}{(2k+3)(2k+9)} = \frac{A}{2k+3} + \frac{B}{2k+9} \ldots …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 06 Oct 2024 17:49:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 5.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-1-p1</link>
            <description>Question 1, Exercise 5.1

Solutions of Question 1 of Exercise 5.1 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 1(i)
$2 x^{3}+3 x^{2}-4 x+1$$x+2$$p(x)=2 x^{3}+3 x^{2}-4 x+1$$x-c=x+2 \implies c=-2$\begin{align*}
\text{Remainder} &amp; = p(c) = p(-2) \\
&amp; = 2(-2)^{3}+3 (-2)^{2}-4 (-2)+1 \\
&amp; = -16+12+8+1 \\
&amp;= 5.
\end{align*}$x^{4}+2 x^{3}-x^{2}+2 x+3$$x-2$\( p(x…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 10 Oct 2024 09:44:24 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 and 3, Exercise 5.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-1-p2</link>
            <description>Question 2 and 3, Exercise 5.1

Solutions of Question 2 and 3 of Exercise 5.1 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $x-3$$x^{3}-2 x^{2}-5 x+6$$p(x)=x^{3}-2 x^{2}-5 x+6$$x-c=x-3$$\implies c=3$$x-3$$p(x)$$p(3)=0$\begin{align*}
p(3)&amp;=3^3-2(3)^2-5(3)+6 \\
&amp; = 27-18-15+6 \\
&amp; = 0.
\end{align*}$x-3$$p(x)$$x-3$$x^{3}-2 x^{2}-5 x+1$$p(x)=x^{3}-2 x^{2}-5 x+1$$x-c=x-3$$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 10 Oct 2024 09:44:46 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 and 5, Exercise 5.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-1-p3</link>
            <description>Question 4 and 5, Exercise 5.1

Solutions of Question 4 and 5 of Exercise 5.1 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $4 y^{3}-4 y^{2}+10+2 y$$4 y^{2}-8 y+10$$q$$x^{3}+q x^{2}-7 x+6$$(x+1)$$p(x)=x^{3}+q x^{2}-7 x+6$$x-c=x+1$$\implies c=-1$$x+1$$p(x)$$p(-1)=0$\begin{align*}
&amp;(-1)^3+q(-1)^2-7(-1)+6=0 \\
-&amp;1+q+7+6=0\\
&amp;q+12=0\\
&amp;q=-12
\end{align*}</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 10 Oct 2024 09:45:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 6 and 7, Exercise 5.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-1-p4</link>
            <description>Question 6 and 7, Exercise 5.1

Solutions of Question 6 and 7 of Exercise 5.1 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $m$$2 x^{3}+3 x^{2}-3 x-m$$x-2$$p(x)=2 x^{3}+3 x^{2}-3 x-m$$x-c=x-2$$\implies c=2$\begin{align*}
\text{Remainder} &amp; = p(c) = p(2) \\
&amp; = 2(2)^{3} + 3(2)^{2} - 3(2) - m \\
&amp; = 2(8) + 3(4) - 3(2) - m \\
&amp; = 16 + 12 - 6 - m \\
&amp; = 22 - m.
\end{align…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 10 Oct 2024 09:45:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 8 and 9, Exercise 5.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-1-p5</link>
            <description>Question 8 and 9, Exercise 5.1

Solutions of Question 8 and 9 of Exercise 5.1 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 x^{3}+3 x^{2}-11 x-6$$p(x)=2x^3+3x^2-11x-6$\begin{align}
p(2) &amp;= 2(2)^3+3(2)^2-11(2)-6 \\
&amp;=16+12-22-6 = 0 \end{align}$p(x)$\begin{align}
\begin{array}{r|rrrr}
2 &amp; 2 &amp; 3 &amp; -11 &amp; -6 \\
&amp; \downarrow  &amp;  4 &amp; 14 &amp; 6 \\
\hline
&amp; 2 &amp; 7 &amp; 3 &amp;  0 \\
\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 10 Oct 2024 09:45:57 +0000</pubDate>
        </item>
        <item>
            <title>Question 10, Exercise 5.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-1-p6</link>
            <description>Question 10, Exercise 5.1

Solutions of Question 10 of Exercise 5.1 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 10
$\left(x^{3}+11 x^{2}+34 x+24\right)$$(x+1)$$p(x)=x^{3}+11 x^{2}+34 x+24$\begin{align}
\begin{array}{r|rrrr}
-1 &amp; 1 &amp; 11 &amp; 34 &amp; 24 \\
&amp; \downarrow  &amp;  -1 &amp; -10 &amp; -24 \\
\hline
&amp; 1 &amp; 10 &amp; 24 &amp;  0 \\
\end{array}\end{align}$$ p(x) = (x+1)(x^2+10…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Thu, 10 Oct 2024 09:46:15 +0000</pubDate>
        </item>
        <item>
            <title>Question 1 and 2, Exercise 5.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-2-p1</link>
            <description>Question 1 and 2, Exercise 5.2

Solutions of Question 1 and 2 of Exercise 5.2 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y^{3}-7 y-6$$f(y)=y^{3}-7 y-6$\begin{align*}
f(-1)&amp;=(-1)^{3}-7 (-1)-6 \\
&amp;= -1+7-6 =0.
\end{align*}$y+1$$f(y)$\begin{align}
\begin{array}{r|rrrr}
-1 &amp; 1 &amp; 0 &amp; -7 &amp; -6 \\
&amp; \downarrow  &amp;  -1 &amp; 1 &amp; 6 \\
\hline
&amp; 1 &amp; -1 &amp; -6 &amp;  0 \\
\end{array}\end…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 5.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-2-p2</link>
            <description>Question 3 and 4, Exercise 5.2

Solutions of Question 3 and 4 of Exercise 5.2 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 x^{3}+5 x^{2}-9 x-18$\( f(x) = 2x^{3} + 5x^{2} - 9x - 18 \)\begin{align*}
f(-2) &amp;= 2(-2)^{3} + 5(-2)^{2} - 9(-2) - 18 \\
&amp;= 2(-8) + 5(4) + 18 - 18 \\
&amp;= -16 + 20 + 18 - 18 = 0.
\end{align*}\( x + 2 \)\( f(x) \)\[
\begin{array}{r|rrrr}
-2 &amp; 2 &amp;…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Exercise 5.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-2-p3</link>
            <description>;

Question 5 and 6, Exercise 5.2

Solutions of Question 5 and 6 of Exercise 5.2 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $t^{3}+t^{2}+3 t-5$\( f(t) = t^{3} + t^{2} + 3t - 5 \)\begin{align*}
f(1) &amp;= (1)^{3} + (1)^{2} + 3(1) - 5 \\
&amp;= 1 + 1 + 3 - 5 \\
&amp;= 0.
\end{align*}\( t - 1 \)\( f(t) \)\begin{align}
\begin{array}{r|rrrr}
1 &amp; 1 &amp; 1 &amp; 3 &amp; -5 \\
&amp;   &amp; 1 &amp; 2 &amp; 5 \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:35 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 and 8, Exercise 5.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-2-p4</link>
            <description>Question 7 and 8, Exercise 5.2

Solutions of Question 7 and 8 of Exercise 5.2 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 x^{3}-15 x^{2}+27 x-10$$\dfrac{1}{2}$\( f(x) \)\( x - \frac{1}{2} \)\begin{align}
\begin{array}{r|rrrr}
\frac{1}{2} &amp; 2 &amp; -15 &amp; 27 &amp; -10 \\
&amp;   &amp; 1   &amp; -7 &amp; 10 \\
\hline
&amp; 2 &amp; -14 &amp; 20 &amp; 0 \\
\end{array}
\end{align}\begin{align*}
f(x) &amp;= \left…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:35 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 5.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-3-p1</link>
            <description>Question 1, Exercise 5.3

Solutions of Question 1 of Exercise 5.3 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 1
$x$$x+3$$x+3+7=x+10$$120 cm^3$\begin{align*}
&amp; x(x+3)(x+10)=120 \\
\implies  &amp; x(x^2+3x+10x+30)-120=0\\
\implies &amp; x^3+13x^2+30x-120=0.
\end{align*}$$p(x)=x^3+13x^2+30x-120$$\begin{align*}
p(2)&amp;=2^3+13(2)^2+30(2)-120 \\
&amp;=8+52+60-120 =0
\end{ali…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:36 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 5.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-3-p2</link>
            <description>Question 2, Exercise 5.3

Solutions of Question 2 of Exercise 5.3 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 2
$t(x)=x^{3}-12 x^{2}+48 x+74$$x$$$t(x)=x^{3}-12 x^{2}+48 x+74.$$$t=12$\begin{align*}
t(12)&amp;=(12)^3-12(12)^2+48(12)+74 \\
&amp;=650.
\end{align*}</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 5.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-3-p3</link>
            <description>Question 3, Exercise 5.3

Solutions of Question 3 of Exercise 5.3 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 3
$x$$2x$$2x+2$\begin{align*}
&amp; x(2x)(2x+2) = 144 \\
\implies &amp; 4x^2(x+1)=144 \\
\implies &amp; x^2(x+1)=36 \\
\implies &amp; x^3+x^2-36=0
\end{align*}$$p(x)=x^3+x^2-36.$$\begin{align*}
p(3)&amp;=3^3+3^2-36 \\
&amp;=27+9-36 = 0
\end{align*}$x=3$$p(x)$$2(3)$$2(3)+…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 5.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-3-p4</link>
            <description>Question 4, Exercise 5.3

Solutions of Question 4 of Exercise 5.3 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 4
$x$$2x+3$$x-2$\begin{align*}
&amp; x(2x+3)(x-2) = 2475 \\
\implies &amp; x(2x^2+3x-4x-6)=2475 \\
\implies &amp; x(2x^2-x-6)-2475=0 \\
\implies &amp; 2x^3-x^2-6x-2475=0
\end{align*}$$p(x)=2x^3-x^2-6x-2475.$$\begin{align*}
p(11)&amp;=2(11)^3-11^2-6(11)-2475 \\
&amp;=2662…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 5, Exercise 5.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-3-p5</link>
            <description>Question 5, Exercise 5.3

Solutions of Question 5 of Exercise 5.3 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 5
$6 x^{2}+38 x+56$$2 x+8$$ACED$$ABFG$$ACED$$6 x^{2}+38 x+56$$2 x+8$\begin{align*}
&amp; 6 x^{2}+38 x+56 \\
= &amp; 2(3x^2+19x+28) \\
= &amp; 2(3x^2+12x+7x+28) \\
= &amp; 2(3x(x+4)+7(x+4)) \\
=&amp; 2(x+4)(3x+7) \\
=&amp; (2x+8)(3x+7)
\end{align*}\begin{align*}
&amp; Length …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 6, Exercise 5.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-3-p6</link>
            <description>Question 6, Exercise 5.3

Solutions of Question 6 of Exercise 5.3 of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 6
$y^3-2y^2-y+2$$y-2$$=p(y)=y^3-2y^2-y+2$$y-2$$y-2$$p(y)$$2$$p(y)$\[
\begin{array}{r|rrrr}
2 &amp; 1 &amp; -2 &amp; -1 &amp; 2 \\
&amp; \downarrow   &amp; 2 &amp; 0 &amp; -2 \\
\hline
&amp; 1  &amp; 0  &amp; -1 &amp; 0 \\
\end{array}
\]\begin{align*}
p(y) &amp; = (y-2)(y^2-1) \\
&amp; = (y-2)(y+1)(y-1)…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/ex5-4-p2</link>
            <description>Question 2, Review Exercise

Solutions of Question 2 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Go to</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:38 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/re-ex-p1</link>
            <description>Question 1, Review Exercise

Solutions of Question 1 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 1
$-2-x+x^{2}$$(x-2)(x-1)$$(x+1)(x+2)$$(x+2)(x-1)$$(x+1)(x-2)$$(x+1)(x-2)$$9 y^{2}+9 y-10$$3 y-2$$ 0$$1$$2$$3$$ 0$$\frac{x^{2}-x-9}{x-3}=x+2+\frac{?}{x-3}$$-27$$-3$$\frac{3}{x-3}+x+2$$ 3$$-3$$3 x^{3}-2 x^{2}+5$$x+1$$x+1$$x^{3}+5 x^{2}-4 x+k$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:39 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 &amp; 3, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/re-ex-p2</link>
            <description>Question 2 &amp; 3, Review Exercise

Solutions of Question 2 &amp; 3 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\left(64 y^{3}-8\right) \div(4 y-2) \quad$\begin{align*}
\frac{(64 y^{3}-8)}{(4 y-2)}&amp;= \frac{(4y - 2)(16y^{2} + 8y + 4)}{4y - 2}\\
&amp; = 16y^{2} + 8y + 4 .\end{align*}$\left(125 y^{3}-8\right) \div(5 y-2)$\begin{align*}
\frac{(125 y^{3}-8)}{(5 …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:39 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 &amp; 5, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/re-ex-p3</link>
            <description>Question 4 &amp; 5, Review Exercise

Solutions of Question 4 &amp; 5 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3 y-2$$6 y^{3}-y^{2}-5 y+2$\begin{align*}3y-2&amp;=0\\
3y&amp;=2\\
y&amp;=\frac{2}{3}\end{align*}\begin{align*}
f(y) &amp;= 6y^{3} - y^{2} - 5y + 2\\
f\left(\frac{2}{3}\right) &amp;= 6\left(\frac{2}{3}\right)^{3} - \left(\frac{2}{3}\right)^{2} - 5\left(\frac{2}{3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 6 &amp; 7, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/re-ex-p4</link>
            <description>Question 6 &amp; 7, Review Exercise

Solutions of Question 6 &amp; 7 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $k$$\left(x^{2}+8 x+k\right)$$(x-4)$\( p(x) = x^{2} + 8x + k \)\( p(x) \)\( (x - 4) \)\( p(4) \)\( p(4) = 0 \)\begin{align*}
p(4) &amp;= (4)^2 + 8(4) + k \\
&amp;= 16 + 32 + k \\
&amp;= 48 + k.
\end{align*}\[
48 + k = 0.
\]\[
k = -48.
\]$3 x^{2}-x+32-\frac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 8, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/re-ex-p5</link>
            <description>Question 8, Review Exercise

Solutions of Question 8 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 8
$y^{3}+6 y^{2}-y-30$$(y-2)$$(y+3)$$p(y)=y^{3}+6 y^{2}-y-30$$(y-2)$$(y+3)$$p(y)$$2$$-3$$p(y)$\[
\begin{array}{r|rrrr}
2 &amp; 1 &amp; 6 &amp; -1 &amp; -30 \\
 &amp; \downarrow   &amp; 2  &amp; 16 &amp; 30  \\
\hline
-3 &amp; 1  &amp; 8  &amp; 15 &amp; 0 \\
 &amp; \downarrow   &amp; -3  &amp; -15 &amp;  …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:41 +0000</pubDate>
        </item>
        <item>
            <title>Question 6, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/re-ex-p6</link>
            <description>Question 6, Review Exercise

Solutions of Question 6 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 6
$k$$\left(x^{2}+8 x+k\right)$$(x-4)$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:42 +0000</pubDate>
        </item>
        <item>
            <title>Question 7, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/re-ex-p7</link>
            <description>Question 7, Review Exercise

Solutions of Question 7 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 7
$3 x^{2}-x+32-\frac{121}{x+4}$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:42 +0000</pubDate>
        </item>
        <item>
            <title>Question 8, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit05/re-ex-p8</link>
            <description>Question 8, Review Exercise

Solutions of Question 8 of Review Exercise of Unit 05: Polynomials. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. 

Question 8
$y^{3}+6 y^{2}-y-30$$(y-2)$$(y+3)$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 13 Oct 2024 17:52:43 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 6.1 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1</link>
            <description>Exercise 6.1 (Solutions)

The solutions of the Exercise 6.1 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to factorial function.$n!$$$
n!=\left\{\begin{array}{l}
n(n-1)(n-2)\cdot \ldots \cdot 3 \cdot 2 \cdot 1 \text{ if } n\geq 1,\\
1 \text{ if } n=0.
\end{array} \right.
$$$10!$$\dfrac{12!}{7! 3! 2!}$$\dfrac{4!-2!}{3!+5!}$$\dfrac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1-p1</link>
            <description>Question 1, Exercise 6.1

Solutions of Question 1 of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $10!$\begin{align*} 
10! &amp;= 10 \times 9 \times 8 \times 7 \times 6 \times 5 \times 4 \\
&amp;= 3628800
\end{align*}$\dfrac{12!}{7! 3! 2!}$\begin{align*}
\dfrac{12!}{7! \, 3! \, 2!} &amp;= \dfrac{12 \times 11 \times 10 \times 9 \times 8 \times 7!}{7! …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:29 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1-p2</link>
            <description>Question 2, Exercise 6.1

Solutions of Question 2 of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\quad 14\cdot 13\cdot 12\cdot 11$\begin{align*}
&amp;14\cdot 13\cdot 12\cdot 11\\
= &amp; \dfrac{14\cdot 13\cdot 12\cdot 11\cdot 10!}{10!} \\
= &amp; \dfrac{14!}{10!} 
\end{align*}$\quad 1\cdot 3\cdot 5 \cdot 7 \cdot 9$$$1 \times 3\times 5\times 7 \time…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:29 +0000</pubDate>
        </item>
        <item>
            <title>Question 3 and 4, Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1-p3</link>
            <description>Question 3 and 4, Exercise 6.1

Solutions of Question 3 and 4 of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\quad \dfrac{1}{5!}+\dfrac{3}{6!}+\dfrac{1}{7!}=\dfrac{4}{315}$\begin{align*}
LHS = &amp; \dfrac{1}{5!}+\dfrac{3}{6!}+\dfrac{1}{7!} \\
= &amp; \dfrac{1}{5!}+\dfrac{3}{6\cdot 5!}+\dfrac{1}{7\cdot 6\cdot 5!}\\
= &amp; \dfrac{1}{5!}\left(1+\dfr…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:31 +0000</pubDate>
        </item>
        <item>
            <title>Question 5, Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1-p4</link>
            <description>Question 5, Exercise 6.1

Solutions of Question 5 of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\quad \dfrac{n}{(n-4)!}=\dfrac{3.3!}{(n-3)!}$\begin{align*}
\dfrac{n}{(n-4)!}&amp;=\dfrac{3.3!}{(n-3)!}\\
\dfrac{n}{(n-4)!}&amp;=\dfrac{3.3!}{(n-3)(n-4)!}\\
n&amp;=\dfrac{3\times 6}{n-3}\\
n(n-3)&amp;=18\\
n^2-3n&amp;=18\\
n^2-2n-18&amp;=0\\
n^2+3n-6n-18&amp;=0\\
n(…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 6(i-v), Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1-p5</link>
            <description>Question 6(i-v), Exercise 6.1

Solutions of Question 6(i-v) of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n\in N$$\quad (2n)!=2^n(n!)[1\cdot3\cdot5 \cdots (2n-1)]$\begin{align*}
(2n)!&amp;= (2n)(2n-1)(2n-2)(2n-3)\cdots (2n-n)(2n-(n+1))\cdots4.3.2.1\\
&amp;= (2n)(2n-1)(2n-2)(2n-3)\cdots (n)(n-1)\cdots4.3.2.1\\
&amp;= (2n)(2n-1)(2n-2)(2n-3)\cdots (n…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 6(vi-ix), Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1-p6</link>
            <description>Question 6(vi-ix), Exercise 6.1

Solutions of Question 6(vi-ix) of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n\in N$$\quad 33!$$2^{15}$$$33!=33.32.31\cdots4.3.2.1$$$2,4,8,16,32$$2^1,2^2,2^3,2^4,2^5$\begin{align*}33!&amp;=2^5.2^4.2^3.2^2.2(33\times31\times\cdots6\times5\times3\times1)\\
&amp;=2^{15}(33\times31\times\cdots\times3\times1)\end{al…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:34 +0000</pubDate>
        </item>
        <item>
            <title>Question 7(i-vi), Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1-p7</link>
            <description>Question 7(i-vi), Exercise 6.1

Solutions of Question 7(i-vi) of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\quad \dfrac{n!}{(n-2)!}=930,\quad n \geq 2$\begin{align*}
\dfrac{n!}{(n-2)!}&amp;=930\\
\dfrac{n(n-1)(n-2)!}{(n-2)!}&amp;=930\\
n(n-1)&amp;=930\\
n^2-n-930&amp;=0
\end{align*}\begin{align*}
n&amp;=\dfrac{1\pm \sqrt{1+4(930)}}{2}\\
&amp;=\dfrac{1\pm …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:37 +0000</pubDate>
        </item>
        <item>
            <title>Question 7(vii-xi), Exercise 6.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-1-p8</link>
            <description>Question 7(vii-xi), Exercise 6.1

Solutions of Question 7(vii-xi) of Exercise 6.1 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\quad n!=990 \cdot (n-3)!$\begin{align*}
n!&amp;=990  (n-3)!\\
n(n-1)(n-1)(n-3)!&amp;=990  (n-3)!\\
n(n-1)(n-1)&amp;=990 \\
n^3-3n^2+2n-990 &amp;=0\\
\end{align*}\[\begin{array}{c|cccc}
 &amp; 1 &amp; -3 &amp; 2 &amp; -990 \\  
11 &amp; 0  &amp; 11 &amp; 88 &amp; 990 \\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:36 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 6.2 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2</link>
            <description>Exercise 6.2 (Solutions)

The solutions of the Exercise 6.1 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to factorial function.$n!$$$
n!=\left\{\begin{array}{l}
n(n-1)(n-2)\cdot \ldots \cdot 3 \cdot 2 \cdot 1 \text{ if } n\geq 1,\\
1 \text{ if } n=0.
\end{array} \right.
$$$n \in \mathbb{N}$${ }^n P_r=\frac{n!}{(n-r)!}$$\quad{ }^…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:59 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p1</link>
            <description>Question 1, Exercise 6.2

Solutions of Question 1 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n \in N$$\quad^nP_r=\dfrac{n!}{(n-r)!}$$n$$r$$\dot{n}$$2^{\text {nd }}$$(n-1)$$3^{\text {rd }}$$(n-2)$$r^{\text {th }}$$(n-(r-1)$$$
{ }^{n} P_{r}=n(n-1)(n-2) \ldots(n-(r-1))
$$$(n-r)(n-r-1) \ldots 3,2.1$${ }^{n} P_{r}=\frac{n(n-1)(n-2)\ldots…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p2</link>
            <description>Question 2, Exercise 6.2

Solutions of Question 2 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\quad ^nP_4=20\, ^nP_2$\begin{align*}
\dfrac{m}{(n-4)!}&amp;=20 \cdot \dfrac{m}{(n-2)!}\\
\dfrac{1}{(n-4)!}&amp;=\dfrac{20}{(n-2)(n-3)(n-4)!}\\
(n-2)(n-3)&amp;=20\\
n^{2}-5 n+6&amp;=20\\
n^{2}-5 n-14&amp;=0\\
n^{2}+2 n-7 n-14&amp;=0\\
n(n+2)-7(n+2)&amp;=0\\
(n+2)(n-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:49 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p3</link>
            <description>Question 3, Exercise 6.2

Solutions of Question 3 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $r$$^6P_{r-1}=^5P_4$\begin{align*}{ }^{6} P_{r-1}&amp;={ }^{5} P_{4}\\
\dfrac{6!}{(6-(r-1))!}&amp;=\dfrac{5!}{(5-4)!}\\
\dfrac{6!}{(7-r)!}&amp;=\dfrac{5!}{1!} \\
\frac{6 \times 5!}{(7-r)!}=\dfrac{5!}{1}
6&amp;=(7-r)!\\
3!&amp;=(7-r)!\\
3&amp;=7-r \\
r&amp;=7-3\\
r&amp;=4\en…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:50 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 and 5, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p4</link>
            <description>Question 4 and 5, Exercise 6.2

Solutions of Question 4 and 5 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3$$1,2,3,4,5,6,$$3$$6$$\mathrm{I}:$$2$$$\underline{ },\underline{ },\underline{2}$$$={ }^{5} P_{2}=20$$4$$$\underline{ },\underline{ },\underline{4}$$$={ }^{5} P_{2}=20$$6$$$\underline{ },\underline{ },\underline{6}$$$={ }^{5} P_…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:51 +0000</pubDate>
        </item>
        <item>
            <title>Question 6 and 7, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p5</link>
            <description>Question 6 and 7, Exercise 6.2

Solutions of Question 6 and 7 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $4$$$1,2,3,4,5,6$$6$$6$$6$$6$$$\text{Total possibilities }6 \times 6 \times 6 \times 6=6^4=1296$$$1,1,2,2,3,3,4$$=7$$2^{\text {nd }}$$6^{\text {th }}$$1^{\text {st }}, 3^{\text {rd }}, 5^{\text {th }}$$7^{\text {th }}$$2,2,4$$1,1,…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:54 +0000</pubDate>
        </item>
        <item>
            <title>Question 8 and 9, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p6</link>
            <description>Question 8 and 9, Exercise 6.2

Solutions of Question 8 and 9 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $4$$5$$5$$4$$41$$=41 \times 41=576$$2$$3$$4$$$\text{Total flags} =9$$$$\text{Repetition of blue }=2$$$$\text{Repetition of yellow}=3$$$$\text{Repetition of green}=4$$\begin{align*}\text{Total signals }&amp;=\dfrac{9!}{2!3!4!}\\
&amp;=\dfr…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:54 +0000</pubDate>
        </item>
        <item>
            <title>Question 10 and 11, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p7</link>
            <description>Question 10 and 11, Exercise 6.2

Solutions of Question 10 and 11 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $=6$$={ }^{6}{ }^{1} P_{5}=6$$720$$F$$F$$5$$5!=120$$=9$$S=2$$T=2$$A=2$\begin{align*}\text{possible permutation}&amp;=\dfrac{9!}{2!2!2!}\\
&amp;=\dfrac{362880}{8}\\
&amp;=45360\end{align*}</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:56 +0000</pubDate>
        </item>
        <item>
            <title>Question 12 and 13, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p8</link>
            <description>Question 12 and 13, Exercise 6.2

Solutions of Question 12 and 13 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $=5$$5$$=5!=120$$O$$E$$21=2$$3$$3!= 6$$O$$E$$=6 \times 2=12$$0$$E$$=120-12=108$$=7$$7$$=71=5040$$3$$A, I$$E$$3$$4$$$5!=120$$$3$$=6$$$6 \times 120=\mathbf{7 2 0}$$$5040$$720$$3$$5040-720=4320$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:55 +0000</pubDate>
        </item>
        <item>
            <title>Question 14 and 15, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p9</link>
            <description>Question 14 and 15, Exercise 6.2

Solutions of Question 14 and 15 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3$$=7$$=3$$={ }^{7} P_{3}=\dfrac{7!}{4!}=210$$5$$3$$2$$3$$=31=6$$=(5!\times 3!\times 2!) \times 31=8640$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:57 +0000</pubDate>
        </item>
        <item>
            <title>Question 16 and 17, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p10</link>
            <description>Question 16 and 17, Exercise 6.2

Solutions of Question 16 and 17 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $1,2,3,4,5,6$$1, 3$$5$$=3 \times{ }^{5} P_{5}=360$$4$$1,2,3,4$$5$$1$$={ }^{4} P_{3}=24$$3$$24$$5$$24$$24+24+24=72$$4$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:43 +0000</pubDate>
        </item>
        <item>
            <title>Question 18 and 19, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p11</link>
            <description>Question 18 and 19, Exercise 6.2

Solutions of Question 18 and 19 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $10,000$$0,2,3,5,6$$4$$10000$$3$$5$$0$$3={ }^{3} P=6$$0$$5=3 p_{6}=6$$10000$$5$$=6+6=12$$3$$4$$5$$={ }^{4} P_{3}=2$$4$$5$$4$$5={ }^{4} P_{3}=24$$3$$3$$3$$5=$${ }^{4} P_{2}=12$$3$$5$$3$$5=$${ }^{4} P_{2}=12$$2$$3$$2$$5={ }^{4} …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:48 +0000</pubDate>
        </item>
        <item>
            <title>Question 20 and 21, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p12</link>
            <description>Question 20 and 21, Exercise 6.2

Solutions of Question 20 and 21 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $6$$6$$5!$$6$$6!$$=5! \times 6!=86400$$= n = 4$$= {}^4P_4 = 24.$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:45 +0000</pubDate>
        </item>
        <item>
            <title>Question 22 and 23, Exercise 6.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-2-p13</link>
            <description>Question 22 and 23, Exercise 6.2

Solutions of Question 22 and 23 of Exercise 6.2 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $(3\quad 4\quad 6\quad 1\quad 5\quad2)$$1$$2$$L=1, A=2, H=3, O=4, R=5, E=6$$(3,4,6,1,5,2)=$$(4\quad 6\quad 3\quad 2\quad 1\quad5)$$(4,6,3,2,1,5)$$4^{\text {th }}$$2^{\text {nd }}$$6^{\text {th }}$$3^{\text {rd }}$$3^{\text {rd…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 08:59:46 +0000</pubDate>
        </item>
        <item>
            <title>Exercise 6.3 (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3</link>
            <description>Exercise 6.3 (Solutions)

The solutions of the Exercise 6.3 of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. This exercise consists of the question related to factorial function.$n \in \mathbb{N}$${ }^{n} C_{r}=\frac{n!}{r!(n-r)!}$$n,{ }^{n-1} C_{r-1}=(n-r+1){ }^{n} C_{r-1}$$r^{n} C_{r}=(n-r+1)^{n} C_{r-1}$${ }^{n-1} C_{r-1}+{ }^{n-1} C_{r}={ }^{n} C_{r}$${ }^{n} C_{r}+{ }^{n} C…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:35 +0000</pubDate>
        </item>
        <item>
            <title>Question 1(i-v), Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p1</link>
            <description>Question 1(i-v), Exercise 6.3

Solutions of Question 1(i-v) of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n\in N$$\quad^nC_r=\dfrac{n!}{r!(n-r)!}$$n$$r$$0&lt;r&lt;n$$X$$r$$r$$r$$$
\begin{array}{ll} 
&amp; r!X={ }^{n} P_{r} \\
\Rightarrow &amp; r!X=\frac{n!}{(n-r)!} \\
\Rightarrow &amp; X=\frac{n!}{r!(n-r)!}={ }^{n}{C}_{r}
\end{array}
$$$n\in N$$n\cdot^{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:24 +0000</pubDate>
        </item>
        <item>
            <title>Question 1(vi-x), Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p2</link>
            <description>Question 1(vi-x), Exercise 6.3

Solutions of Question 1(vi-x) of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n\in N$$\quad^{2n}C_n=\dfrac{2^n[1.3.5.\cdots(2n-1)]}{n!}$\begin{align*}L.H.S &amp;=\quad^{2n}C_n \\
&amp;=\dfrac{(2 n)!}{n!(2 n-n)!}\\
&amp;=\dfrac{(2 n)(2 n-1)(2 n-2)(2 n-n)(2 n-(n+1)) ..2 .1}{n!\cdot n!}\\
&amp;=\dfrac{(2 n)(2 n-1)(2 n-2) ..(…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:26 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p3</link>
            <description>Question 2, Exercise 6.3

Solutions of Question 2 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$\,\, ^nC_5=\,\, ^nC_8$\begin{align*}\dfrac{n!}{5!(n-5)!}=\dfrac{n!}{8!(n-8)!}&amp;\\
\dfrac{1}{8!(n-5)(n-6)(n-7)(n-8)!}&amp;\\
=\dfrac{1}{8 \times 7 \times 6 \times 8!(n-8)!}&amp;\\
336=(n-5)(n-6)(n-7)&amp;\\
(n-5)\left(n^{2}-13 n+42\right)&amp;=336\\
n^{3}-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:26 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p4</link>
            <description>Question 3, Exercise 6.3

Solutions of Question 3 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $r$$\quad^{15}C_{3r}= ^{15}C_{3+r}$$${ }^{n} C_{r}={ }^{n} C_{n-r}$$\begin{align*}n=15\quad&amp;\text{put} \quad r=3 r\\
n-3 r&amp;=r+3\\
15-3 r&amp;=r+3 \\
15-3 &amp; =3 r+r \\
12 &amp; =4 r\\
r&amp;=3\end{align*}$r$$\quad^{8}C_{r}-\,^7C_3= ^{7}C_{2}$\begin{align*}…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:27 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p5</link>
            <description>Question 4, Exercise 6.3

Solutions of Question 4 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$r$$\,\,^nC_{r-1}:\,^nC_{r}:\,^nC_{r+1}=6:14:21$\begin{align*}\dfrac{n!}{(r-1)!(n-(r-1))!}&amp;: \dfrac{n!}{r!(n-r)!}\\
: \dfrac{n!}{(r+1)!(n-(r+1))!} &amp;= 6:14:21\\
\dfrac{1}{(r-1)!(n-r+1)!}: \dfrac{1}{r!(n-r)!}&amp;\\
: \dfrac{1}{(r+1)!(n-r-1)!}&amp;=…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:27 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p6</link>
            <description>Question 5 and 6, Exercise 6.3

Solutions of Question 5 and 6 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $11$$16$$11$$16$${ }^{16} C_{11}$$4368$$11$$11$$16$$10$$15$$$
{ }^{15} C_{10}=3003
$$$5$$3$$3$$1$${ }^{5} C_{1}$$2$${ }^{3} C_{2}$$={ }^{5} C_{1} \times{ }^{3} C_{2}=5 \times 3=15$$2$$={ }^{5} C_{2} \times{ }^{3} C_{1}=10 \times 3…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:29 +0000</pubDate>
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        <item>
            <title>Question 7 and 8, Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p7</link>
            <description>Question 7 and 8, Exercise 6.3

Solutions of Question 7 and 8 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $5$$6$$4$$2$$2$$3$$={ }^{4} C_{2} \times{ }^{6} C_{3}=6 \times 20=120$$5$$6$$4$$2$$2$$2$$2,3$$2$$120$$3$$2$$={ }^{4} C_{3} \cdot{ }^{6} C_{2}=4 \times 15=60$$4$$={ }^{4} C_{4} \times{ }^{6} C_{1}=1 \times 6=6$$=120+60+6=186$$5$$6$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:29 +0000</pubDate>
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        <item>
            <title>Question 9 and 10, Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p8</link>
            <description>Question 9 and 10, Exercise 6.3

Solutions of Question 9 and 10 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$n$$n$$n$$C_{2}$$n$$n$$={ }^{n} C_{2}-n$$=\frac{n!}{2!(n-2)!}-n$$10$$10$$3$$7$$10$${ }^{10} C_{7}$$7$$3$$7={ }^{10} C_{7}=120$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:33 +0000</pubDate>
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        <item>
            <title>Question 11 and 12, Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p9</link>
            <description>Question 11 and 12, Exercise 6.3

Solutions of Question 11 and 12 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $n$$35$$n$\begin{align*}{ }^{n} C_{2}-n&amp;=35\\
\text{or} \quad \dfrac{n!}{2!(n-2)!}-n&amp;=35\\
\dfrac{n(n-1)(n-2)!}{2(n-2)!}-n&amp;=35\\
\dfrac{n(n-1)-2 n}{2}&amp;=35\\
n^{2}-n-2 n&amp;=70\\
n^{2}-3 n-70&amp;=0\\
n^{2}+7 n-10 n-70 &amp; =0 \\
n(n+7)-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:31 +0000</pubDate>
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        <item>
            <title>Question 13 and 14, Exercise 6.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/ex6-3-p10</link>
            <description>Question 13 and 14, Exercise 6.3

Solutions of Question 13 and 14 of Exercise 6.3 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $6$$1$$1$$2$$6$$1$$6={ }^{6} C_{1}=6$$2$$6={ }^{6} C_{2}=15$$3$$6={ }^{6} C_{3}=20$$4$$6={ }^{6} C_{4}=15$$5$$6={ }^{6} C_{5}=6$$6$$6={ }^{6} C_{6}=1$$$\text{Total}\quad =6+15+20+15+6+1=63$$$A$$B$$C$$8$$5$$A$$3$$B$$C$$5$$8$$A$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:22 +0000</pubDate>
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        <item>
            <title>Question 1, Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/re-ex6-p1</link>
            <description>Question 1, Review Exercise 6

Solutions of Question 1 of Review Exercise 6 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $3\,\,^nP_3=^nP_4$$n$$5$$6$$7$$8$$6$$ 480$$600$$720$$840$$720$$r$$r!$$(r+1)!$$r!+1$$ 2r!$$r!$$6$$\dfrac{5}{2}\,\,6!$$6!$$\dfrac{1}{2}\,\,6!$$\dfrac{3}{2}\,\,6!$$\dfrac{5}{2}\,\,6!$$A=\{1,2,3,4,...,20\}. $$3$$5$$7$$8$$8$$A=\{1,3,5,7,…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:36 +0000</pubDate>
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        <item>
            <title>Question 2 and 3, Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/re-ex6-p2</link>
            <description>Question 2 and 3, Review Exercise 6

Solutions of Question 2 and 3 of Review Exercise 6 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $4$$26$$$^{26}P_4=358800$$$3$$0$$3$$100&#039;s$$9$$3$$$=10\times 10\times10=1000$$$0$$10$$3-$$0$$$=10\times 10=100$$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:43 +0000</pubDate>
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        <item>
            <title>Question 4, 5 and 6, Review Exercise 6</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/re-ex6-p3</link>
            <description>Question 4, 5 and 6, Review Exercise 6

Solutions of Question 4, 5 and 6 of Review Exercise 6 of Unit 06: Permutation and Combination. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $0,2,3,4,5,7$$6$$$=6!=720$$$0$$5$$$5!=120$$$6-$$$=720-120=600$$$7$$$(7-1)!=720$$$2$$$\dfrac{720}{2}=360$$$11!$$10!$$$=11!-10!=36288000$$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:38 +0000</pubDate>
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        <item>
            <title>Review Exercise (Solutions)</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit06/rev-ex</link>
            <description>Review Exercise (Solutions)

The solutions of the Review Exercise of book “Model Textbook of Mathematics for Class XI” published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan are given on this page. 

Question 1.$4$$3$$0$$6$$0,2,3,4,5,7$$7$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 08 Mar 2025 09:00:41 +0000</pubDate>
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        <item>
            <title>Question 1, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p1</link>
            <description>Question 1, Exercise 8.1

Solutions of Question 1 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\cos (\alpha \pm \beta), \sin (\alpha \pm \beta)$$\tan (\alpha \pm \beta)$$\alpha=180^{\circ}, \beta=60^{\circ}$$\alpha=180^{\circ}$$\beta=60^{\circ}$\begin{align*}
 \cos (\alpha + \beta) &amp; = \cos \alpha \cos \beta - \sin \alpha \sin \beta \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:30 +0000</pubDate>
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        <item>
            <title>Question 2, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p2</link>
            <description>Question 2, Exercise 8.1

Solutions of Question 2 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\cos 15^{\circ}$$\cos \left(45^{\circ}-30^{\circ}\right)$\begin{align*}
\cos 15^{\circ} &amp; = \cos \left(45^{\circ}-30^{\circ}\right)\\
&amp;= \cos 45 \cos 30 + \sin 45 \sin 30 \\
&amp;= \dfrac{1}{\sqrt{2}}\cdot \dfrac{\sqrt{3}}{2} + \dfrac{1}{\sqrt{2…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:35 +0000</pubDate>
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        <item>
            <title>Question 3, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p3</link>
            <description>Question 3, Exercise 8.1

Solutions of Question 3 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\cos 120^{\circ}$$\cos \left(180^{\circ}-60^{\circ}\right)$$\cos \left(90^{\circ}+30^{\circ}\right)$\begin{align*}
\cos 120^{\circ} &amp; = \cos \left(180^{\circ}-60^{\circ}\right) \\
&amp;= - \cos 60 ^{\circ}\\
&amp;= -\dfrac{1}{2}.
\end{align*}\begin{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:37 +0000</pubDate>
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        <item>
            <title>Question 4, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p4</link>
            <description>Question 4, Exercise 8.1

Solutions of Question 4 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\cos 6 \theta \cos 3 \theta-\sin 6 \theta \sin 3 \theta$\begin{align*}
&amp; \cos 6 \theta \cos 3 \theta-\sin 6 \theta \sin 3 \theta \\
&amp; = \cos (6\theta +3\theta) \\
&amp; = \cos 9\theta .
\end{align*}$\cos 7 \theta \cos 2 \theta+\sin 7 \theta \sin…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:38 +0000</pubDate>
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        <item>
            <title>Question 5 and 6, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p5</link>
            <description>Question 5 and 6, Exercise 8.1

Solutions of Question 5 and 6 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin \alpha=\dfrac{4}{5}, \tan \beta=-\dfrac{5}{12}$$\cos (\alpha+\beta)$$\cos (\alpha-\beta)$$\sin \alpha=\dfrac{4}{5}$$\alpha$$\tan \beta=-\dfrac{5}{12}$$\beta$$$\cos \alpha=\pm \sqrt{1-\sin^2\alpha}.$$$\alpha$$\cos$\begin{alig…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:39 +0000</pubDate>
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        <item>
            <title>Question 7, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p6</link>
            <description>Question 7, Exercise 8.1

Solutions of Question 7 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\alpha$$\beta$$\sin \alpha=\dfrac{12}{13}$$\tan \beta=\dfrac{4}{3}$$\sin(\alpha+\beta)$$\cos(\alpha+\beta)$$\tan(\alpha+\beta)$$\sin \alpha=\dfrac{12}{13}$$\alpha$$\tan \beta=\dfrac{4}{3}$$\beta$$$\cos \alpha=\pm \sqrt{1-\sin^2\alpha}.$$\(\a…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:39 +0000</pubDate>
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        <item>
            <title>Question 8, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p7</link>
            <description>Question 8, Exercise 8.1

Solutions of Question 8 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin \alpha=\dfrac{3}{5}$$0&lt;\alpha&lt;\dfrac{\pi}{2}$$\cos \beta=\dfrac{12}{13}$$\dfrac{3 \pi}{2}&lt;\beta&lt;2 \pi$$\csc (\alpha+\beta)$$\sec (\alpha+\beta)$$\cot (\alpha+\beta)$$\sin \alpha=\dfrac{3}{5}$$0&lt;\alpha&lt;\dfrac{\pi}{2}$$\alpha$\begin{align…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:41 +0000</pubDate>
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        <item>
            <title>Question 9, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p8</link>
            <description>Question 9, Exercise 8.1

Solutions of Question 9 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\alpha$$\beta$$\sin \alpha=\dfrac{1}{\sqrt{2}}$$\cos \beta=-\dfrac{3}{5}$$\sin (\alpha \pm \beta)$$\sin \alpha=\dfrac{1}{\sqrt{2}}$$\alpha$$\cos \beta=-\dfrac{3}{5}$$\beta$$$\cos \alpha=\pm \sqrt{1-\sin^2\alpha}.$$$\alpha$$\cos$\begin{align*…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:41 +0000</pubDate>
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        <item>
            <title>Question 10, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p9</link>
            <description>Question 10, Exercise 8.1

Solutions of Question 10 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin \left(\dfrac{\pi}{2}-\alpha\right)=\cos \alpha$\begin{align*}
L.H.S &amp; = \sin \left(\frac{\pi}{2}-\alpha\right) \\
&amp; =\sin\frac{\pi}{2} \cos \alpha - \cos \frac{\pi}{2} \sin\alpha \\
&amp; = 1\times \cos \alpha - 0 \times \sin\alpha \\
&amp; =…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:42 +0000</pubDate>
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        <item>
            <title>Question 11, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p10</link>
            <description>Question 11, Exercise 8.1

Solutions of Question 11 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{\sin \left(180^{\circ}+\lambda\right) \cos \left(270^{\circ}+\lambda\right)}{\sin \left(180^{\circ}-\lambda\right) \cos \left(270^{\circ}-\lambda\right)}=1$\begin{align*}
L.H.S &amp; = \dfrac{\sin \left(180^{\circ}+\lambda\right) \cos \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:31 +0000</pubDate>
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        <item>
            <title>Question 12, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p11</link>
            <description>Question 12, Exercise 8.1

Solutions of Question 12 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\alpha+\beta+\gamma=180^{\circ}$$\tan \alpha+\tan \beta+\tan \gamma=\tan \alpha \tan \beta \tan \gamma$$$\alpha+\beta+\gamma=180^{\circ}$$\begin{align*}
&amp; \alpha+\beta=180^{\circ}-\gamma \\
\implies &amp; \tan(\alpha+\beta) = \tan(180^{\circ}-…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:31 +0000</pubDate>
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        <item>
            <title>Question 13, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p12</link>
            <description>Question 13, Exercise 8.1

Solutions of Question 13 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $r \sin (\theta+\phi)$$12 \sin \theta-5 \cos \theta$$12=r\cos \varphi $$-5=r\sin \varphi$\begin{align*}
&amp; (12)^2+(-5)^2=r^2 \cos^2\varphi+r^2 \sin^2 \varphi \\
\implies &amp; 144+25={{r}^{2}}\left( {{\cos }^{2}}\varphi +{{\sin }^{2}}\varphi  \r…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:53:32 +0000</pubDate>
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        <item>
            <title>Question 14, Exercise 8.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-1-p13</link>
            <description>Question 14, Exercise 8.1

Solutions of Question 14 of Exercise 8.1 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\theta$$\sin \theta$$\cos \theta$$\alpha$\begin{align*}
&amp;\tan\alpha = \frac{\overline{BC}}{\overline{AB}} \\
\implies &amp;\tan\alpha = \frac{3}{3} = 1 \\
\implies &amp;\alpha = \tan^{-1}(1) = 45^\circ
\end{align*}$45^\circ$$\theta$\begin{align*}
…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 20 Oct 2024 17:54:47 +0000</pubDate>
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        <item>
            <title>Question 1, 2 and 3 Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p1</link>
            <description>Question 1, 2 and 3 Exercise 8.2

Solutions of Question 1, 2 and 3 of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $P(-3,4)$$\theta$$\theta$$\cos 2 \theta$$\sin 2 \theta$$2 \theta$$x=-3$$y=4$\begin{align*}
r&amp;= \sqrt{(-3)^2+4^2} \\
&amp;=\sqrt{25} = 5.
\end{align*}$$\sin\theta = \frac{4}{5} \text{ and } \cos\theta = -\frac{3}{5}.$$\begin{align…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:35 +0000</pubDate>
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        <item>
            <title>Question 4 Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p2</link>
            <description>Question 4 Exercise 8.2

Solutions of Question 4 of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin 2 \theta$$\cos 2 \theta$$\tan 2 \theta$$\sin \frac{\theta}{2}$$\cos \frac{\theta}{2}$$\tan \frac{\theta}{2}$$\cos \theta=\frac{3}{5}$$0&lt;\theta&lt;\frac{\pi}{2}$$\cos\theta=\dfrac{3}{5}$$0&lt;\theta&lt;\dfrac{\pi}{2}$$\theta$$$\sin\theta = \pm \sq…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:40 +0000</pubDate>
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        <item>
            <title>Question 5 Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p3</link>
            <description>Question 5 Exercise 8.2

Solutions of Question 5 of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin \theta$$\cos \theta$$\tan \theta$$\sin 2 \theta=\frac{24}{25}, 2 \theta$$\sin 2\theta=\dfrac{24}{25}$$2\theta$$$\cos 2\theta = \pm \sqrt{1-\sin^2 2\theta}$$$2\theta$$\cos 2\theta$\begin{align*}\cos 2\theta &amp; = - \sqrt{1-\sin^2 2\theta}\\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:42 +0000</pubDate>
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        <item>
            <title>Question 6 Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p4</link>
            <description>Question 6 Exercise 8.2

Solutions of Question 6 of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin 15^{\circ} \cos 15^{\circ}$$$\sin 2 \theta = 2\sin\theta \cos\theta$$$$\sin\theta \cos\theta = \frac{1}{2}\sin 2\theta$$$\theta = 15^{\circ}$\begin{align*}
\sin 15^{\circ} \cos 15^{\circ} &amp; = \frac{1}{2}\sin 2(15^{\circ}) \\
&amp; \frac{1}{2…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:45 +0000</pubDate>
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        <item>
            <title>Question 7 Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p5</link>
            <description>Question 7 Exercise 8.2

Solutions of Question 7 of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$\sin ^{2} \alpha \cos ^{2} \alpha$$\begin{align*}
\sin ^{2} \alpha \cos ^{2} \alpha &amp;= \left(\frac{1-\cos 2\alpha}{2} \right)\left(\frac{1+\cos 2\alpha}{2} \right)\\
&amp;= \frac{1}{4}(1-\cos^2 2\alpha) \\
&amp;=\frac{1}{4}\left(1-\frac{1+\cos 4\alp…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:47 +0000</pubDate>
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        <item>
            <title>Question 8(i, ii &amp; iii) Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p6</link>
            <description>Question 8(i, ii &amp; iii) Exercise 8.2

Solutions of Question 8(i, ii &amp; iii) of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $(\sin \theta+\cos \theta)^{2}=1+\sin 2 \theta$\begin{align*}
LHS &amp; = (\sin \theta+\cos \theta)^{2} \\
&amp;=\sin^2\theta + \cos^2\theta +2\sin \theta \cos\theta\\
&amp;= 1+2\sin \theta \cos\theta \quad (\because \sin^2\theta…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:48 +0000</pubDate>
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        <item>
            <title>Question 8(iv, v &amp; vi) Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p7</link>
            <description>Question 8(iv, v &amp; vi) Exercise 8.2

Solutions of Question 8(iv, v &amp; vi) of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\csc 2 \alpha=\dfrac{\tan \alpha+\cot \alpha}{2}$\begin{align*}
RHS &amp; = \dfrac{\tan \alpha+\cot \alpha}{2} \\
&amp; = \dfrac{1}{2}\left(\frac{\sin\alpha}{\cos\alpha}+\frac{\cos\alpha}{\sin\alpha} \right)\\
\end{align*}$8 \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:50 +0000</pubDate>
        </item>
        <item>
            <title>Question 8(vii, viii &amp; ix) Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p8</link>
            <description>Question 8(vii, viii &amp; ix) Exercise 8.2

Solutions of Question 8(vii, viii &amp; ix) of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin 2 \theta=2 \cot \theta \sin ^{2} \theta$\begin{align*}
RHS &amp;= 2 \cot \theta \sin ^{2} \theta\\
&amp;= 2 \frac{\cos \theta }{\sin \theta} \sin ^{2} \theta\\
&amp;= 2 \cos \theta \sin\theta\\
&amp;=  \sin2 \theta\\
&amp;=LH…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:53 +0000</pubDate>
        </item>
        <item>
            <title>Question 8(x, xi &amp; xii) Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p9</link>
            <description>Question 8(x, xi &amp; xii) Exercise 8.2

Solutions of Question 8(x, xi &amp; xii) of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sec 2 x=\dfrac{\cos x}{\cos x+\sin x}+\dfrac{\sin x}{\cos x-\sin x}$\begin{align*}
RHS &amp;= \dfrac{\cos x}{\cos x+\sin x}+\dfrac{\sin x}{\cos x-\sin x}\\
&amp;=\dfrac{\cos x(\cos x-\sin x)+\sin x(\cos x+\sin x)}{(\cos x+\…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:54 +0000</pubDate>
        </item>
        <item>
            <title>Question 8(xiii, xiv &amp; xv)  Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p10</link>
            <description>Question 8(xiii, xiv &amp; xv)  Exercise 8.2

Solutions of Question 8(xiii, xiv &amp; xv) of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\csc 2 \alpha-\cot 2 \alpha=\tan \alpha$\begin{align*}
LHS &amp;= \csc 2 \alpha-\cot 2 \alpha\\
&amp;=\frac{1}{\sin 2 \alpha}- \frac{\cos2 \alpha}{\sin 2\alpha }\\
&amp;=\frac{1-\cos2 \alpha}{\sin2 \alpha}\\
&amp;= \frac{2\si…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:56:27 +0000</pubDate>
        </item>
        <item>
            <title>Question 8(xvi, xvii &amp; xviii)  Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p11</link>
            <description>Question 8(xvi, xvii &amp; xviii)  Exercise 8.2

Solutions of Question 8(xvi, xvii &amp; xviii) of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{1-\cos ^{2} \beta}{2-2 \cos \beta}=\cos ^{2} \dfrac{\beta}{2}$\begin{align*}
LHS &amp;= \dfrac{1-\cos ^{2} \beta}{2-2 \cos \beta}\\
&amp;= \dfrac{\sin ^{2} \beta}{2-2 \cos \beta}\\
&amp;=\dfrac{4\sin ^{2} \fr…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:56:02 +0000</pubDate>
        </item>
        <item>
            <title>Question 8(xix, xx, xxi &amp; xxii)  Exercise 8.2</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-2-p12</link>
            <description>Question 8(xix, xx, xxi &amp; xxii)  Exercise 8.2

Solutions of Question 8(xix, xx, xxi &amp; xxii) of Exercise 8.2 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$\frac{\sin 2 \alpha}{\sin \alpha}-\frac{\cos 2 \alpha}{\cos \alpha}=\sec \alpha$$\begin{align*}
LHS &amp;= \dfrac{\sin 2 \alpha}{\sin \alpha}-\frac{\cos 2 \alpha}{\cos \alpha}\\
&amp;= \dfrac{\sin 2 \alpha …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 26 Oct 2024 18:54:46 +0000</pubDate>
        </item>
        <item>
            <title>Question 1(i, ii, iii &amp; iv)  Exercise 8.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-3-p1</link>
            <description>Question 1(i, ii, iii &amp; iv)  Exercise 8.3

Solutions of Question 1(i, ii, iii &amp; iv) of Exercise 8.3 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$4 \sin 16x \cos 10x $$\begin{align*}
&amp;4 \sin 16x \cos 10x \\
&amp; = 2 (2\sin 16x \cos 10x) \\
&amp;= 2[\sin(16x+10x)+\sin(16x-10x)]\\
&amp;= 2[\sin (26x)+\sin(6x)]
\end{align*}$10 \cos 10y \cos 6y$\begin{align*}
&amp;10 \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 28 Oct 2024 17:14:30 +0000</pubDate>
        </item>
        <item>
            <title>Question 1(v, vi, vii &amp; viii) Exercise 8.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-3-p2</link>
            <description>Question 1(v, vi, vii &amp; viii) Exercise 8.3

Solutions of Question 1(v, vi, vii &amp; viii) of Exercise 8.3 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $ \sin(-u) \sin 5u$\begin{align*}
&amp;\sin(-u) \sin 5u \\
=&amp; -\sin u \sin 5u \\
=&amp; -\frac{1}{2}[\cos(u - 5u) - \cos(u + 5u)] \\
= &amp;-\frac{1}{2}[\cos(-4u) - \cos(6u)] \\
=&amp; \frac{1}{2}[\cos(6u) - \cos(4u) ]
\e…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 28 Oct 2024 17:14:29 +0000</pubDate>
        </item>
        <item>
            <title>Question 1(ix, x &amp; xi) Exercise 8.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-3-p3</link>
            <description>Question 1(ix, x &amp; xi) Exercise 8.3

Solutions of Question 1(ix, x &amp; xi) of Exercise 8.3 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 \sin 75{\circ} \sin 15{\circ}$\begin{align*}
&amp;\quad2 \sin 75^{\circ} \sin 15^{\circ} \\
&amp;= \cos(75^{\circ} - 15^{\circ}) - \cos(75^{\circ} + 15^{\circ}) \\
&amp;= \cos 60^{\circ} - \cos 90^{\circ} \\
\end{align*}$4 \sin …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 28 Oct 2024 17:14:30 +0000</pubDate>
        </item>
        <item>
            <title>Question 2(i, ii, iii, iv and v) Exercise 8.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-3-p4</link>
            <description>Question 2(i, ii, iii, iv and v) Exercise 8.3

Solutions of Question 2(i, ii, iii, iv and v) of Exercise 8.3 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin 70^{\circ} + \sin 30^{\circ}$\begin{align*}
 &amp; \quad \sin 70^{\circ} + \sin 30^{\circ} \\
&amp; = 2 \sin \left(\frac{70+30}{2} \right) \cos \left(\frac{70-30}{2} \right) \\
&amp; = 2 \sin \left(\frac{1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 28 Oct 2024 17:14:31 +0000</pubDate>
        </item>
        <item>
            <title>Question 3(i, ii, iii, iv &amp; v) Exercise 8.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-3-p5</link>
            <description>Question 3(i, ii, iii, iv &amp; v) Exercise 8.3

Solutions of Question 3(i, ii, iii, iv &amp; v) of Exercise 8.3 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{\cos (\alpha + \beta)}{\cos(\alpha - \beta)}=\dfrac{1- \tan \alpha \tan \beta}{1+ \tan \alpha \tan \beta}$\begin{align*}
RHS &amp; = \dfrac{1- \tan \alpha \tan \beta}{1+ \tan \alpha \tan \beta} \\
&amp; …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 28 Oct 2024 17:14:31 +0000</pubDate>
        </item>
        <item>
            <title>Question 3(vi, vii, viii, ix &amp; x) Exercise 8.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-3-p6</link>
            <description>Question 3(vi, vii, viii, ix &amp; x) Exercise 8.3

Solutions of Question 3(vi, vii, viii, ix &amp; x) of Exercise 8.3 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2\tan y \cos 3y= \sec y(\sin 4y-\sin 2y)$\begin{align*}
LHS &amp; = 2\tan y \cos 3y \\
&amp; = 2 \cdot \frac{\sin y}{\cos y} \cos 3y \\
&amp; = \sec y (2 \cos 3y \sin y) \\
&amp; = \sec y \left(\sin (3y+y)-\sin (…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 28 Oct 2024 17:14:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 3(xi, xii &amp; xiii) Exercise 8.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-3-p7</link>
            <description>Question 3(xi, xii &amp; xiii) Exercise 8.3

Solutions of Question 3(xi, xii &amp; xiii) of Exercise 8.3 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2\cos2u \cos u-\sin 2u \sin u=2\cos^3 u$\begin{align*}
LHS &amp; = 2\cos 2u \cos u - \sin 2u \sin u \\
&amp; = 2\left(\cos^2 u - \sin^2 u\right) \cos u - 2\sin u \cos u \sin u \\
&amp; = 2\cos^3 u - 2\sin^2 u \cos u \\
&amp; =…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 28 Oct 2024 17:14:32 +0000</pubDate>
        </item>
        <item>
            <title>Question 4 Exercise 8.3</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/ex8-3-p8</link>
            <description>Question 4 Exercise 8.3

Solutions of Question 4 of Exercise 8.3 of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\cos 80^{\circ} \cos 60^{\circ} \cos 40^{\circ} \cos 20^{\circ}=\dfrac{1}{16}$\begin{align*}
LHS &amp;= \cos 80^\circ \cos 60^\circ \cos 40^\circ \cos 20^\circ \\
&amp;= \cos 80^\circ \left(\frac{1}{2}\right) \cos 40^\circ \cos 20^\circ \\
&amp;= \frac{1…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Mon, 28 Oct 2024 17:14:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p1</link>
            <description>Question 1, Review Exercise

Solutions of Question 1 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin \left(45^{\circ}-30^{\circ}\right)=\ldots$$\frac{\sqrt{6}-\sqrt{2}}{4}$$\frac{\sqrt{6}+\sqrt{2}}{4}$$\frac{\sqrt{6}-\sqrt{2}}{2}$$\frac{\sqrt{3}-\sqrt{2}}{2}$$\frac{\sqrt{6}-\sqrt{2}}{4}$$\tan \left(\frac{\pi}{6}+\frac{\pi}{4}\rig…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 17:48:41 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p2</link>
            <description>Question 2, Review Exercise

Solutions of Question 2 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin \theta=\dfrac{3}{5}, \sin \phi=\dfrac{5}{13}$$\theta$$\phi$$\sin (\theta-\phi)$$\sin \theta=\dfrac{3}{5}$$\sin \phi=\dfrac{5}{13}$$\theta$$\phi$\begin{align*}
\cos^2 \theta &amp;= 1-\sin^2\theta\\
&amp;= 1-\left(\frac{3}{5}\right)^2\\
&amp; =…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:31:57 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p3</link>
            <description>Question 3, Review Exercise

Solutions of Question 3 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\frac{1}{\sqrt{2}}(\sin \beta+\cos \beta)$\begin{align*}
&amp;\frac{1}{\sqrt{2}}(\sin \beta+\cos \beta)\\
=&amp; \sin \frac{\pi}{4}\sin \beta+\cos \frac{\pi}{4}\cos \beta\\
=&amp; \cos(\beta -\frac{\pi}{4})
\end{align*}$\frac{1}{\sqrt{2}} \sin 75^…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:32:33 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p4</link>
            <description>Question 4, Review Exercise

Solutions of Question 4 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{1+\tan 15^{\circ}}{1-\tan 15^{\circ}}$\begin{align*}
&amp;\frac{1+\tan 15^{\circ}}{1-\tan 15^{\circ}}\\
=&amp;\frac{1+\tan 15^{\circ}}{1-1 \cdot \tan 15^{\circ}}\\
=&amp;\frac{\tan 45^{\circ} + \tan 15^{\circ}}{1 - \tan 45^{\circ} \tan 15^{…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:33:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p5</link>
            <description>Question 5 and 6, Review Exercise

Solutions of Question 5 and 6 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\tan \theta$$\tan \left(\theta-45^{\circ}\right)=\frac{1}{3}$\begin{align*}
&amp; \frac{\tan \theta - \tan 45^{\circ}}{1 + \tan \theta \cdot \tan 45^{\circ}} =\frac{1}{3}\\
\implies &amp; \frac{\tan \theta - 1}{1 + \tan \theta}= \f…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:44:48 +0000</pubDate>
        </item>
        <item>
            <title>Question 7, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p6</link>
            <description>Question 7, Review Exercise

Solutions of Question 7 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\dfrac{4 \sin ^{2} \theta \cos \theta}{\cos 3 \theta+\cos \theta}=\tan 2 \theta \tan \theta$\begin{align*}
LHS&amp;=\frac{4 \sin^2 \theta \cos \theta}{\cos 3 \theta + \cos \theta}\\
&amp;=\frac{4 \sin \theta\sin \theta \cos \theta}{4\cos^ 3 \t…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:47:22 +0000</pubDate>
        </item>
        <item>
            <title>Question 8, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p7</link>
            <description>Question 8, Review Exercise

Solutions of Question 8 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$\sqrt{\frac{\cos \left(90^{\circ}+x\right) \sec (-x) \tan \left(180^{\circ}-x\right)}{\sec \left(360^{\circ}-x\right) \sin \left(180^{\circ}+x\right) \cot \left(90^{\circ}-x\right)}}=i .$$\begin{align*}
LHS&amp;= \sqrt{\frac{\cos \left(90…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:47:40 +0000</pubDate>
        </item>
        <item>
            <title>Question 9, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p8</link>
            <description>Question 9, Review Exercise

Solutions of Question 9 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $$\sqrt{\frac{\left(1-\tan ^{2} x \cos (-x) \cos \left(360^{\circ}-x\right)\right) \tan 45^{\circ}}{\left\{\sin 90^{\circ}-\sin \left(180^{\circ}+x\right)\right\}\left\{\sin 90^{\circ}-\cos \left(90^{\circ}-x\right)\right\}}}$$\begin{al…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:49:13 +0000</pubDate>
        </item>
        <item>
            <title>Question 10, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit08/re-ex-p9</link>
            <description>Question 10, Review Exercise

Solutions of Question 10 of Review Exercise of Unit 08: Fundamental of Trigonometry. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin (16 x)=16 \sin (x) \cos (x) \cos (2 x) \cos (4 x) \cos (8 x)$\begin{align*}
RHS&amp;=16 \sin (x) \cos (x) \cos (2 x) \cos (4 x) \cos (8 x) \\
&amp;= 8(2 \sin (x) \cos (x) )\cos (2 x) \cos (4 x) \cos (8 x) \\
&amp;=  8 \sin2 (x) \cos (2 x) \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sat, 09 Nov 2024 18:51:06 +0000</pubDate>
        </item>
        <item>
            <title>Question 1, Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p1</link>
            <description>Question 1, Exercise 9.1

Solutions of Question 1 of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=2-2 \operatorname{Cos} \theta$\begin{align*} -1 \leq \operatorname{Cos} \theta \leq 1 \end{align*}$-2$\begin{align*} &amp; 2 \geq -2 \operatorname{Cos} \theta \geq -2 \end{align*}$2$\begin{align*}
 &amp; 4 \geq 2-2 \operatorname{Cos} \theta \geq 0 \\
…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:09 +0000</pubDate>
        </item>
        <item>
            <title>Question 2, Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p2</link>
            <description>Question 2, Exercise 9.1

Solutions of Question 2 of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=\dfrac{1}{4+3 \operatorname{Sin} \theta}$\begin{align*} -1 \leq \operatorname{Sin} \theta \leq 1 \end{align*}$3$\begin{align*}  -3 \leq 3 \operatorname{Sin} \theta \leq 3 \end{align*}$4$\begin{align*}
 &amp; 1 \leq 4+3 \operatorname{Sin} \theta \l…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 3, Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p3</link>
            <description>Question 3, Exercise 9.1

Solutions of Question 3 of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=7 \cos 4x$\begin{align*} 
&amp; -1\leq \cos 4x \leq 1 \,\, \forall \,\, x\in \mathbb{R} \\
\implies &amp; -7\leq 7 \cos 4x \leq 7 \\
\end{align*}$= ]-\infty, \infty[ = \mathbb{R}$$=[-7,7]$$y=\cos \frac{x}{3}$\begin{align*} 
&amp; -1\leq \cos \frac{x}{3} \…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:11 +0000</pubDate>
        </item>
        <item>
            <title>Question 4(i-iv), Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p4</link>
            <description>Question 4(i-iv), Exercise 9.1

Solutions of Question 4(i-iv) of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=\sin x+x \cdot \cos x$$f(x)=\sin x+x \cdot \cos x$\begin{align*} f(-x)  = \sin (-x) + (-x)\cdot \cos (-x) \end{align*}$\sin(-x)=-\sin x$$\cos (-x) = \cos x$\begin{align*}
f(x) &amp; = -\sin x - x \cdot \cos x \\
&amp; = -(\sin x + x \cdot …</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:11 +0000</pubDate>
        </item>
        <item>
            <title>Question 4(v-viii), Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p5</link>
            <description>Question 4(v-viii), Exercise 9.1

Solutions of Question 4(v-viii) of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=\dfrac{\sin ^{2} x}{x+\tan x}$\[y = \frac{\sin^2 x}{x + \tan x}\]\begin{align*}
y(-x) &amp;= \frac{\big(-\sin x\big)^2}{-x - \tan x} \\
&amp;= \frac{\sin^2 x}{-x - \tan x}\\
&amp; = \frac{\sin^2 x}{-(x + \tan x)}\\
&amp; = -\frac{\sin^2 x}{x +…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:12 +0000</pubDate>
        </item>
        <item>
            <title>Question 5(i-v), Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p6</link>
            <description>Question 5(i-v), Exercise 9.1

Solutions of Question 5(i-v) of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=2 \operatorname{Sin} x$$y=2 \operatorname{Cos} 3 x$$y=2 \operatorname{Tan} 2 x$$\mathrm{y}=\operatorname{Cos} \frac{\mathrm{x}}{2}$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:13 +0000</pubDate>
        </item>
        <item>
            <title>Question 5(vi-x), Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p7</link>
            <description>Question 5(vi-x), Exercise 9.1

Solutions of Question 5(vi-x) of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=2 \operatorname{Sin} 3 x$$y=3 \operatorname{Cos} x$$y=\operatorname{Cos}^{2} x$$y=\operatorname{Sin}^{2} x$$y=\operatorname{Tan}^{2} x$$y=\operatorname{Sin} \frac{x}{2}$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:14 +0000</pubDate>
        </item>
        <item>
            <title>Question 6, Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p8</link>
            <description>Question 6, Exercise 9.1

Solutions of Question 6 of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=6 \sec(2 x-3)$$\sec$$2\pi$\begin{align*}
6 \sec(2 x-3) &amp; = 6 \sec(2 x-3+2\pi) \\
&amp; = 6 \sec(2(x+\pi)-3)
\end{align*}$6 \sec(2 x-3)$$\pi$$y=\cos (5 x+4)$$\cos$$2\pi$\begin{align*}
\cos (5 x+4) &amp; = 6 \cos(5x+4+2\pi) \\
&amp; = \cos\left(5\left(x+\fr…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:15 +0000</pubDate>
        </item>
        <item>
            <title>Question 7 &amp; 8, Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p9</link>
            <description>Question 7 &amp; 8, Exercise 9.1

Solutions of Question 7 &amp; 8 of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $y=\operatorname{Sin} x$$y=\operatorname{Sin} 2 x$$[0,2 \pi]$$y=\operatorname{Cos} x$$y=\operatorname{Cos} 2 x$$[0,2 \pi]$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:15 +0000</pubDate>
        </item>
        <item>
            <title>Question 9, Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p10</link>
            <description>Question 9, Exercise 9.1

Solutions of Question 9 of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\sin x=\cos x$$\cos x=x$$\sin x=x$$\tan x=x$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:09 +0000</pubDate>
        </item>
        <item>
            <title>Question 10, Exercise 9.1</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/ex9-1-p11</link>
            <description>Question 10, Exercise 9.1

Solutions of Question 10 of Exercise 9.1 of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $ V(t)=a \operatorname{Sin}(k(t-d))+c$$56 \mathrm{~Hz} A C$$k$</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:10 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 and 3,Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-1-p2</link>
            <description>Question 2 and 3,Review Exercise

Solutions of Question 2 and 3 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:17 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-1-p3</link>
            <description>Question 4, Review Exercise

Solutions of Question 4 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:18 +0000</pubDate>
        </item>
        <item>
            <title>Question 1,Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p1</link>
            <description>Question 1,Review Exercise

Solutions of Question 1 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\cos \theta=\frac{\sqrt{3}}{2}$$\sin \theta=$$\frac{1}{2}$$-\frac{1}{2}$$\sqrt{3}$$-\frac{2}{\sqrt{3}}$$-\frac{1}{2}$$\tan (-15 \pi)=$$ 0$$-1$$1$$0$$2 \sin \theta+\frac{1}{2}cosec \theta \theta $$\theta=45^{\circ}$$\frac{1}{\sqrt{2}}$$\frac…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:18 +0000</pubDate>
        </item>
        <item>
            <title>Question 2 and 3, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p2</link>
            <description>Question 2 and 3, Review Exercise

Solutions of Question 2 and 3 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\cos \theta -\sin \theta=\sqrt{2}\sin \theta,$$\cos \theta+ \sin \theta=\sqrt{2} \cos \theta$$$\cos \theta -\sin \theta=\sqrt{2}\sin \theta$$\begin{align*}
&amp; \cos \theta=\sqrt{2}\sin \theta + \sin \theta \\
\implies &amp; \cos \the…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 16:04:15 +0000</pubDate>
        </item>
        <item>
            <title>Question 4, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p3</link>
            <description>Question 4, Review Exercise

Solutions of Question 4 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:20 +0000</pubDate>
        </item>
        <item>
            <title>Question 5 and 6, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p4</link>
            <description>Question 5 and 6, Review Exercise

Solutions of Question 5 and 6 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:22 +0000</pubDate>
        </item>
        <item>
            <title>Question 7, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p5</link>
            <description>Question 7, Review Exercise

Solutions of Question 7 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:22 +0000</pubDate>
        </item>
        <item>
            <title>Question 8, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p6</link>
            <description>Question 8, Review Exercise

Solutions of Question 8 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:23 +0000</pubDate>
        </item>
        <item>
            <title>Question 9, Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p7</link>
            <description>Question 9, Review Exercise

Solutions of Question 9 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:23 +0000</pubDate>
        </item>
        <item>
            <title>Question 10(i-v), Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p8</link>
            <description>Question 10(i-v), Review Exercise

Solutions of Question 10(i-v) of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:24 +0000</pubDate>
        </item>
        <item>
            <title>Question 10(vi-x), Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p9</link>
            <description>Question 10(vi-x), Review Exercise

Solutions of Question 10(vi-x) of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:24 +0000</pubDate>
        </item>
        <item>
            <title>Question 10(xi-xv), Review Exercise</title>
            <link>https://www.mathcity.org/math-11-nbf/sol/unit09/re-ex-p10</link>
            <description>Question 10(xi-xv), Review Exercise

Solutions of Question 10(xi-xv) of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan.</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Wed, 27 Nov 2024 15:59:19 +0000</pubDate>
        </item>
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