atan(3*x) 3*3 *log(3) ------------------- 2 1 + 9*x
atan(3*x) 9*3 *(-6*x + log(3))*log(3) ----------------------------------- 2 / 2\ \1 + 9*x /
/ 2 2 \ atan(3*x) | log (3) 72*x 18*x*log(3)| 27*3 *|-2 + -------- + -------- - -----------|*log(3) | 2 2 2 | \ 1 + 9*x 1 + 9*x 1 + 9*x / ------------------------------------------------------------- 2 / 2\ \1 + 9*x /