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 /
$$\frac{1}{\left(9 x^{2} + 1\right)^{2}} \left(- 108 x \operatorname{atan}{\left (3 x \right )} + 18\right)$$
/ 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 /
$$\frac{1}{\left(9 x^{2} + 1\right)^{2}} \left(\frac{3888 x^{2} \operatorname{atan}{\left (3 x \right )}}{9 x^{2} + 1} - \frac{972 x}{9 x^{2} + 1} - 108 \operatorname{atan}{\left (3 x \right )}\right)$$