Question

Find the x-intercepts for the parabola defined by the equation below. y = 2x2 + 2x - 4

Answer 1

2 x² + 2 x - 4 = 0
2 x² + 4 x - 2 x - 4 = 0
2 x ( x + 2 ) - 2 ( x + 2 ) = 0
( x + 2 ) ( 2 x - 2 ) 0 0
x + 2 = 0,         or :  2 x - 2 = 0
x = - 2,                    2 x = 2,  x = 1
The x-intercepts are: ( -2, 0 ) and ( 1, 0 ).