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

Question

Mathematics

Brady

21 February, 17:27

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

+4

Answers (2)

Know the Answer?

Mireya Hogan · Answer 1

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

Sabrina Hinton · Answer 2

Sabrina Hinton 21 February, 21:11

0

The roots are x=0,4,-2