The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 1.1738\\[1 em]x_2 &= -0.0869+1.3025i\\[1 em]x_3 &= -0.0869-1.3025i \end{aligned} $$Polynomial $ 2x^3-2x^2+3x-4 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.