This package supplies a set of functions that find the roots of
polynomials. Polynomials up to the quartic may be solved directly by
numerical formulae. Polynomials of fifth and higher powers will be
solved by an iterative method, as there are no general solutions for
fifth and higher powers.

The linear, quadratic, cubic, and quartic *_roots() functions all
expect to have a non-zero value for the $a term.

If the constant term is zero then the first value returned in the list
of answers will always be zero, for all functions.

WWW: https://metacpan.org/release/Math-Polynomial-Solve