The third derivative
[src]
/ / 3\ 3 2/ 3\ 6 3/ 3\ 6 / 3\\
| 3 cos\x / 9*x *cos \x / 9*x *cos \x / 9*x *cos\x /|
6*|- 9*x + ------- - ------------- + ------------- + ------------|
| / 3\ 2/ 3\ 3/ 3\ / 3\ |
\ sin\x / sin \x / sin \x / sin\x / /
$$6 \left(\frac{9 x^{6} \cos{\left(x^{3} \right)}}{\sin{\left(x^{3} \right)}} + \frac{9 x^{6} \cos^{3}{\left(x^{3} \right)}}{\sin^{3}{\left(x^{3} \right)}} - 9 x^{3} - \frac{9 x^{3} \cos^{2}{\left(x^{3} \right)}}{\sin^{2}{\left(x^{3} \right)}} + \frac{\cos{\left(x^{3} \right)}}{\sin{\left(x^{3} \right)}}\right)$$