$$x^3-13x-36 = 0$$
Answer
$$ \begin{matrix}x_1 = 4.56932 & x_2 = -2.28466+1.63064i & x_3 = -2.28466-1.63064i \end{matrix} $$
Explanation
This polynomial has no rational roots that can be found using Rational Root Test.
Roots were found using qubic formulas.
This page was created using
Polynomial Equations Solver