The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.932\\[1 em]x_2 &= -3.6387\\[1 em]x_3 &= 4.5707 \end{aligned} $$Polynomial $ 4x^3-70x-62 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.