3*x
-------- + atan(3*x)
2
1 + 9*x
$$\frac{3 x}{9 x^{2} + 1} + \operatorname{atan}{\left (3 x \right )}$$
/ 2 \
| 9*x |
6*|1 - --------|
| 2|
\ 1 + 9*x /
----------------
2
1 + 9*x
$$\frac{- \frac{54 x^{2}}{9 x^{2} + 1} + 6}{9 x^{2} + 1}$$
/ 2 \
| 9*x |
216*x*|-1 + --------|
| 2|
\ 1 + 9*x /
---------------------
2
/ 2\
\1 + 9*x /
$$\frac{216 x}{\left(9 x^{2} + 1\right)^{2}} \left(\frac{9 x^{2}}{9 x^{2} + 1} - 1\right)$$