6*atan(3*x)
-----------
2
1 + 9*x
$$\frac{6 \operatorname{atan}{\left(3 x \right)}}{9 x^{2} + 1}$$
18*(1 - 6*x*atan(3*x))
----------------------
2
/ 2\
\1 + 9*x /
$$\frac{18 \left(- 6 x \operatorname{atan}{\left(3 x \right)} + 1\right)}{\left(9 x^{2} + 1\right)^{2}}$$
/ 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 /
$$\frac{108 \cdot \left(\frac{36 x^{2} \operatorname{atan}{\left(3 x \right)}}{9 x^{2} + 1} - \operatorname{atan}{\left(3 x \right)} - \frac{9 x}{9 x^{2} + 1}\right)}{\left(9 x^{2} + 1\right)^{2}}$$