1 ------------ 2 x + 2*x + 2
1/(x^2 + 2*x + 2)
1/(2 + x^2 + 2*x)
1 ------------ 2 2 + x + 2*x
1/(2.0 + x^2 + 2.0*x)
1 ------------- 2 + x*(2 + x)
1/(2 + x*(2 + x))