Mathematics · Class 8
Introduction to Graphs
Cartesian plane, coordinates, and linear graphs of equations.
4 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Graphs visually represent data and relationships. Plot points on Cartesian plane, draw line graphs, linear graphs y = mx + c, and interpret motion/time graphs.
Cartesian Plane
- x-axis (horizontal), y-axis (vertical)
- Origin (0,0); point (x,y)
- Quadrants I, II, III, IV
Linear Graphs
Linear
y = mx + c (m = slope, c = y-intercept)
Applications
Distance-time graphs: slope = speed. Constant speed → straight line. Rest → horizontal line.
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Example 1: Plot Point
Plot A(3, −2).
- 1Move 3 right from origin
- 2Move 2 down
Answer
Point in Quadrant IV
Example 2: Linear Graph
Draw y = 2x + 1.
- 1When x=0, y=1
- 2When x=1, y=3
- 3Join points
Answer
Straight line with slope 2
Key Points to Remember
- ✓ Coordinates order is (x, y)
- ✓ Horizontal line: y = constant
- ✓ Vertical line: x = constant
Exam Tips
- • Label axes and scale on graphs
- • Use at least 3 points for line graphs
Practice MCQs — Introduction to Graphs
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Point (−3, 4) lies in: