The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 1.169\\[1 em]x_2 &= 0.2668+0.9811i\\[1 em]x_3 &= 0.2668-0.9811i\\[1 em]x_4 &= -0.8513+0.7188i\\[1 em]x_5 &= -0.8513-0.7188i \end{aligned} $$Polynomial $ 2x^5-x^2-3 $ has no rational roots that can be found using Rational Root Test, so the roots were found using Newton method.