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