/ 6 \ |-------| \x*x - 9/ ----------------- / 6 \ |---------------| \(x + 3)*(x + 3)/
2 (3 + x) -------- 2 -9 + x
1.0*(3.0 + x)^2/(-9.0 + x*x)
2 6*(3 + x) ---------- 2 -54 + 6*x
3 + x ------ -3 + x
2 (3 + x) -------- -9 + x*x
6 1 + ------ -3 + x
2 (x + 3) -------- x*x - 9