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

1 Answer
José F.
Apr 17, 2016

#+-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:

#+-1, +-2#

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

#+-1, 2#

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