The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.0295\\[1 em]x_2 &= 4.5023\\[1 em]x_3 &= -7.5318 \end{aligned} $$Polynomial $ x^3+3x^2-34x+1 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.