Unit 08 Sets and Functions (General Mathematics 9 PCTB)

Notes, solutions of unit 08, General Mathematics 9, for Punjab Curriculum & Textbook Board (PCTB), Lahore.

* Identify pair of real numbers as an ordered pair.

Recognize an ordered pair through different examples.
Describe rectangular or Cartesian plane consisting of two number lines interesting at right angles at the point $O$.
Identify origin $(O)$ and coordinate axes (horizontal and vertical axes or $x-axis$ and $y-axis$) in the rectangular plane.
Locate an ordered pair $(a, b)$ as a point in the rectangular plane and recognize.
- $a$ as the $x$-coordinate (or abscissa),
- $b$ as the $y$-coordinate (or ordinate).
Draw different geometrical shapes (e.g., line segment, triangle and rectangle etc.) by joining a set of given points.
Construct a table for pairs of values satisfying a linear equation in two variables.
Plot the pairs of points to obtain the graph of a given expression.
Choose an appropriate scale to draw a graph.
Draw a graph of
- an equation of the form $y = c$,
- an equation of the form $x = a$,
- an equation of the form $y = mx$,
- an equation of the form $y = mx + c$.
Draw a graph from a given table of (discrete) values.
Solve appropriate real life problems.
Interpret conversion graph as a linear graph relating to two quantities which are in direct proportion.
Read a given graph to know one quantity corresponding to another.
Read the graph for conversions of the form.
- miles and kilometers, acres and hectares,
- degrees Celsius and degrees Fahrenheit,
- Pakistani currency and another currency, etc.
Solve simultaneous linear equations in two variables using graphical method.