The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.2733\\[1 em]x_2 &= 3.8867+2.2402i\\[1 em]x_3 &= 3.8867-2.2402i \end{aligned} $$Polynomial $ 2x^3-15x^2+36x+11 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.