2 9*atan (x) ---------- 2 1 + x
18*(1 - x*atan(x))*atan(x) -------------------------- 2 / 2\ \1 + x /
/ 2 2 \ | 1 2 6*x*atan(x) 4*x *atan (x)| 18*|------ - atan (x) - ----------- + -------------| | 2 2 2 | \1 + x 1 + x 1 + x / ---------------------------------------------------- 2 / 2\ \1 + x /