Let us plot the points (- 3, 6), (- 2, 4), (0, 0), (1, - 2), (2, - 4), (3, - 6) in the coordinate plane on a graph paper Class 9

Let us plot the points (- 3, 6), (- 2, 4), (0, 0), (1, - 2), (2, - 4), (3, - 6) in the coordinate plane on a graph paper Class 9

Question 1.

Let us plot the points (- 3, 6), (- 2, 4), (0, 0), (1, - 2), (2, - 4), (3, - 6) in the coordinate plane on a graph paper. Join the points (- 3, 6) and (3, - 6) using a ruler. Doing so, observe that all five points lie on a straight line. Can you guess the equation of this line by looking at the relationship between the x and y coordinates of each point? Class 9

Answer:

When x = 1, y = -2 = -2 × 1

When x = 2, y = -4 = -2 × 2

When x = 3, y = -6 = -2 × 3

When x = 0, y = 0 = -2 × 0

When x = -2, y = 4 = -2 × -2

When x = -3, y = 6 = -2 × -3

∴ The equation of the line is, y = -2x