1 -------- 2 (x + 2)
1/((x + 2)^2)
(2 + x)^(-2)
1 -------- 2 (2 + x)
0.25/(1 + 0.5*x)^2
1 ------------ 2 4 + x + 4*x
1/(4 + x^2 + 4*x)