The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.2994\\[1 em]x_2 &= -2.5512\\[1 em]x_3 &= 3.6006 \end{aligned} $$Polynomial $ 4x^3-3x^2-38x-11 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.