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        <title>MathCity.org</title>
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            <link>https://www.mathcity.org/</link>
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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>
        </item>
        <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>
        </item>
        <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>
        </item>
        <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>
        </item>
        <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>
        </item>
        <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>
        </item>
        <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>
        </item>
        <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>
        </item>
        <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>
        </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 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>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>
        </item>
        <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>
        </item>
        <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>
        </item>
        <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>
        </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 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>
        <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 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>
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