# How do you find all roots for x^3 - 2x^2 - x + 2 = 0?

Apr 17, 2016

$\pm 1 , 2$

#### Explanation:

Explanation:

We will use the Rational Root Theorem:

If the rational number r/s is a root of a polynomial whose coefficients are integers, then the integer r is a factor of the constant term, and the integer s is a factor of the leading coefficient.

So, if the constant therm is 2 and the leading factor is 1, candidates for roots are:

$\pm 1 , \pm 2$

If we try them, we discover that the roots are:

$\pm 1 , 2$