2*x + 1 ----------- 2 2 x *(x + 1)
(2*x + 1)/((x^2*(x + 1)^2))
x^(-2) - 1/(1 + x)^2
1 1 -- - -------- 2 2 x (1 + x)
(1.0 + 2.0*x)/(x^2*(1.0 + x)^2)
1 + 2*x -------------- 2 4 3 x + x + 2*x
(1 + 2*x)/(x^2 + x^4 + 2*x^3)