/x\
2*atan|-|
\3/
----------
/ 2\
| x |
3*|1 + --|
\ 9 /
$$\frac{2 \operatorname{atan}{\left (\frac{x}{3} \right )}}{\frac{x^{2}}{3} + 3}$$
/ /x\\
6*|3 - 2*x*atan|-||
\ \3//
-------------------
2
/ 2\
\9 + x /
$$\frac{1}{\left(x^{2} + 9\right)^{2}} \left(- 12 x \operatorname{atan}{\left (\frac{x}{3} \right )} + 18\right)$$
/ 2 /x\\
| 4*x *atan|-||
| /x\ 9*x \3/|
12*|- atan|-| - ------ + ------------|
| \3/ 2 2 |
\ 9 + x 9 + x /
--------------------------------------
2
/ 2\
\9 + x /
$$\frac{1}{\left(x^{2} + 9\right)^{2}} \left(\frac{48 x^{2} \operatorname{atan}{\left (\frac{x}{3} \right )}}{x^{2} + 9} - \frac{108 x}{x^{2} + 9} - 12 \operatorname{atan}{\left (\frac{x}{3} \right )}\right)$$