The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 4.4412\\[1 em]x_2 &= -0.7206+0.6176i\\[1 em]x_3 &= -0.7206-0.6176i \end{aligned} $$Polynomial $ 2x^3-6x^2-11x-8 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.