2 3 2 -x - x + x + 2*x + x
-x - x^2 + x^3 + 2*x + x^2
3 x + x
x + x^3
x*(x + I)*(x - I)
(x*(x + i))*(x - i)
x^3 + 1.0*x
/ 2\ x*\1 + x /
x*(1 + x^2)