The third derivative
[src]
/ 2 2 2 \
| 2 1 4*x 6*x*acot(x) 4*x *acot (x)|
2*|1 + acot (x) - ------ - ------ - ----------- - -------------|
| 2 2 2 2 |
\ 1 + x 1 + x 1 + x 1 + x /
----------------------------------------------------------------
2
/ 2\
\1 + x /
$$\frac{2 \left(- \frac{4 x^{2} \operatorname{acot}^{2}{\left(x \right)}}{x^{2} + 1} - \frac{4 x^{2}}{x^{2} + 1} - \frac{6 x \operatorname{acot}{\left(x \right)}}{x^{2} + 1} + \operatorname{acot}^{2}{\left(x \right)} + 1 - \frac{1}{x^{2} + 1}\right)}{\left(x^{2} + 1\right)^{2}}$$