4 1 - x
1 - x^4
(x + 1)*(x - 1)*(x + I)*(x - I)
(((x + 1)*(x - 1))*(x + i))*(x - i)
1.0 - x^4
/ 2\ -(1 + x)*\1 + x /*(-1 + x)
-(1 + x)*(1 + x^2)*(-1 + x)