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