4 x - x
x^4 - x
/ ___\ / ___\ | 1 I*\/ 3 | | 1 I*\/ 3 | x*(x - 1)*|x + - + -------|*|x + - - -------| \ 2 2 / \ 2 2 /
((x*(x - 1))*(x + 1/2 + i*sqrt(3)/2))*(x + 1/2 - i*sqrt(3)/2)
/ 2\ x*(-1 + x)*\1 + x + x /
x*(-1 + x)*(1 + x + x^2)
/ 3\ x*\-1 + x /
x*(-1 + x^3)