Question

Draw the graph of y = x² – 5x – 6 and hence solve x² – 5x – 14 = 0.

Answer 1

Draw the parabola using the points (-5, 44), (-4, 30), (-3, 18), (-2, 8), (-1, 0), (0, -6), (1, -10), (2, -12), (3, -12), (4, -10)

To solve the equation x² – 5x – 14 = 0, subtract x² – 5x – 14 = 0 from y² = x – 5x – 6.

The co-ordinates of the points of intersection of the line and the parabola forms the solution set for the equation x² – 5x – 14 = 0.

∴ Solution {-2, 7}