The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.9223\\[1 em]x_2 &= -0.2112+0.8236i\\[1 em]x_3 &= -0.2112-0.8236i \end{aligned} $$Polynomial $ 6x^3-3x^2+2x-4 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.