The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.8351\\[1 em]x_2 &= 0.4176+1.0115i\\[1 em]x_3 &= 0.4176-1.0115i \end{aligned} $$Polynomial $ 2x^3+x+2 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.