Question

Find the zeros of the polynomial function f(x)=x^3-2x^2-8x

Answer 1

The roots are x=0,4,-2

Answer 2

First factor out that x
f(x)=x(x^2-2x-8)
what 2 numbers multiply to get -8 and add to get -2?
-4 and 2
f(x)=(x-0)(x-4)(x+2)
set to zero
x-0=0
x=0

x-4=0
x=4

x+2=0
x=-2

the zeroes are at x=-2,0 and 4