$$h^3+3h^2+h+1 = 0$$
Answer
$$ \begin{matrix}h_1 = -2.76929 & h_2 = -0.11535+0.58974i & h_3 = -0.11535-0.58974i \end{matrix} $$
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