/ /x\ \
| x*acos|-| |
| 54 \3/ | /x\
-|------- + -----------|*acos|-|
| 2 3/2| \3/
|-9 + x / 2\ |
| | x | |
| |1 - --| |
\ \ 9 / /
---------------------------------
9
$$- \frac{1}{9} \left(\frac{x \operatorname{acos}{\left (\frac{x}{3} \right )}}{\left(- \frac{x^{2}}{9} + 1\right)^{\frac{3}{2}}} + \frac{54}{x^{2} - 9}\right) \operatorname{acos}{\left (\frac{x}{3} \right )}$$
2/x\ /x\ 2 2/x\
acos |-| 18*x*acos|-| x *acos |-|
2 \3/ \3/ \3/
- ------------- - ------------- + ------------ - --------------
3/2 3/2 2 5/2
/ 2\ / 2\ / 2\ / 2\
| x | | x | \-9 + x / | x |
9*|1 - --| 9*|1 - --| 27*|1 - --|
\ 9 / \ 9 / \ 9 /
$$- \frac{x^{2} \operatorname{acos}^{2}{\left (\frac{x}{3} \right )}}{27 \left(- \frac{x^{2}}{9} + 1\right)^{\frac{5}{2}}} + \frac{18 x \operatorname{acos}{\left (\frac{x}{3} \right )}}{\left(x^{2} - 9\right)^{2}} - \frac{\operatorname{acos}^{2}{\left (\frac{x}{3} \right )}}{9 \left(- \frac{x^{2}}{9} + 1\right)^{\frac{3}{2}}} - \frac{2}{9 \left(- \frac{x^{2}}{9} + 1\right)^{\frac{3}{2}}}$$