/ 2\ acot\x /
acot(x^2)
-2*x ------ 4 1 + x
/ 4 \ | 4*x | 2*|-1 + ------| | 4| \ 1 + x / --------------- 4 1 + x
/ 4 \ 3 | 8*x | 8*x *|5 - ------| | 4| \ 1 + x / ----------------- 2 / 4\ \1 + x /