The roots of polynomial $ p(s) $ are:
$$ \begin{aligned}s_1 &= -0.2735\\[1 em]s_2 &= -2.7533\\[1 em]s_3 &= 0.0134+1.1524i\\[1 em]s_4 &= 0.0134-1.1524i \end{aligned} $$Polynomial $ s^4+3s^3+2s^2+4s+1 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.