The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 1.327\\[1 em]x_2 &= -0.6635+1.3493i\\[1 em]x_3 &= -0.6635-1.3493i \end{aligned} $$Polynomial $ 2x^3+x-6 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.