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 /