2 9
-3 - 3*cot (a) + ----------- + 9*cos(a)
________
/ 2
\/ 1 - a
$$9 \cos{\left(a \right)} - 3 \cot^{2}{\left(a \right)} - 3 + \frac{9}{\sqrt{1 - a^{2}}}$$
/ / 2 \ 3*a \
3*|-3*sin(a) + 2*\1 + cot (a)/*cot(a) + -----------|
| 3/2|
| / 2\ |
\ \1 - a / /
$$3 \left(\frac{3 a}{\left(1 - a^{2}\right)^{\frac{3}{2}}} + 2 \left(\cot^{2}{\left(a \right)} + 1\right) \cot{\left(a \right)} - 3 \sin{\left(a \right)}\right)$$
/ 2 2 \
| / 2 \ 3 2 / 2 \ 9*a |
3*|-3*cos(a) - 2*\1 + cot (a)/ + ----------- - 4*cot (a)*\1 + cot (a)/ + -----------|
| 3/2 5/2|
| / 2\ / 2\ |
\ \1 - a / \1 - a / /
$$3 \left(\frac{9 a^{2}}{\left(1 - a^{2}\right)^{\frac{5}{2}}} - 2 \left(\cot^{2}{\left(a \right)} + 1\right)^{2} - 4 \left(\cot^{2}{\left(a \right)} + 1\right) \cot^{2}{\left(a \right)} - 3 \cos{\left(a \right)} + \frac{3}{\left(1 - a^{2}\right)^{\frac{3}{2}}}\right)$$