The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 1.0815\\[1 em]x_2 &= -1.0815\\[1 em]x_3 &= 0.5407+0.9366i\\[1 em]x_4 &= 0.5407-0.9366i\\[1 em]x_5 &= -0.5407+0.9366i\\[1 em]x_6 &= -0.5407-0.9366i \end{aligned} $$Polynomial $ 2000x^6-3200 $ has no rational roots that can be found using Rational Root Test, so the roots were found using Newton method.