The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -2.0899\\[1 em]x_2 &= 3.3756\\[1 em]x_3 &= 0.8571+0.3403i\\[1 em]x_4 &= 0.8571-0.3403i \end{aligned} $$Polynomial $ x^4-3x^3-4x^2+11x-6 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.