2 / 2 \ x*\x + 1/
x*(x^2 + 1)^2
1*(x + 0)*(x + I)*(x - I)
((1*(x + 0))*(x + i))*(x - i)
x*(1.0 + x^2)^2
5 3 x + x + 2*x
x + x^5 + 2*x^3