The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -3.1952\\[1 em]x_2 &= 0.3476+1.2651i\\[1 em]x_3 &= 0.3476-1.2651i \end{aligned} $$Polynomial $ 2x^3+5x^2-x+11 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.