How do you find all roots for #x^3 - 2x^2 - x + 2 = 0#?
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:
If we try them, we discover that the roots are: