Question

What are the x-intercepts of the function f(x) = –x2 – x + 2?

(–2, 0) and (1, 0)
(2, 0) and (1, 0)
(–2, 0) and (-1, 0)
(0, -2) and (0, 1)

Answer 1

Set f(x)=0: −x^2 − x + 2 = 0 ⇒ multiply by −1: x^2 + x − 2 = 0 ⇒ (x+2)(x−1)=0.
So x = −2 or x = 1. The x-intercepts are (−2, 0) and (1, 0).