Question

find all zeros of the following function:
f(x)=x^3-x^2+4x-4
I have (x^2+4)(x+1)

so one zero is 1. how do i find the two other zeros.

Answer 1

if +1 is a zero, (x-1) is a factor because (x-1) is zero when x = 1

Answer 2

I have
(x^2+4)(x-1)
then when is (x^2 + 0 x +4 )= 0??
x = [ 0 +/- sqrt (0 -16) ] / 2
x = +/- 2 i (imaginary roots)