2 acot (x)
acot(x)^2
-2*acot(x) ---------- 2 1 + x
2*(1 + 2*x*acot(x)) ------------------- 2 / 2\ \1 + x /
/ 2 \ | 3*x 4*x *acot(x) | 4*|- ------ - ------------ + acot(x)| | 2 2 | \ 1 + x 1 + x / ------------------------------------- 2 / 2\ \1 + x /