10*atan(5*x) ------------ 2 1 + 25*x
50*(1 - 10*x*atan(5*x)) ----------------------- 2 / 2\ \1 + 25*x /
/ 2 \ | 15*x 100*x *atan(5*x)| 500*|-atan(5*x) - --------- + ----------------| | 2 2 | \ 1 + 25*x 1 + 25*x / ----------------------------------------------- 2 / 2\ \1 + 25*x /