Question

What are the real zeros of the function g(x)=x^3+2x^2-x-2

Answer 1

g(-2) = -8 + 2(-2)^2 -(-2) - 2
= -8 + 8 + 2 - 2 = 0

so x = -2 is one zero and (x + 2) is a factor of g(x)

use long division to divide g(x) by (x + 2) we get x^2 - 1

x^2 -1 = 0 gives x = 1 or -1

So answer is -1, 1 and -2.