2 atan (3*x) + 5
atan(3*x)^2 + 5
6*atan(3*x) ----------- 2 1 + 9*x
18*(1 - 6*x*atan(3*x)) ---------------------- 2 / 2\ \1 + 9*x /
/ 2 \ | 9*x 36*x *atan(3*x)| 108*|-atan(3*x) - -------- + ---------------| | 2 2 | \ 1 + 9*x 1 + 9*x / --------------------------------------------- 2 / 2\ \1 + 9*x /