# How do you use the rational roots theorem to find all possible zeros of #x^3-x^2-4x+4#?

##### 1 Answer

Aug 20, 2016

#### Answer:

(see below for use of the Rational Root Theorem)

#### Explanation:

The Rational Root Theorem tells us that the rational zeros of

#color(red)(1)x^3-x^2-4x+color(blue)(4)#

are the factors of#(color(blue)(4))/(color(red)(1))#

Checking each of the possible factors we get:

which gives us zeros for

#x=-2, x=1, and x=2#

Since

it can have a maximum of

and we have found them all.