The third derivative
[src]
2
4*x 3 3*x
1 - ------ - ------------------- + ------------------
2 / 2\ 2 / 2\
1 + x 8*\1 + x /*acot (x) 2*\1 + x /*acot(x)
-----------------------------------------------------
2
/ 2\ _________
\1 + x / *\/ acot(x)
$$\frac{- \frac{4 x^{2}}{x^{2} + 1} + \frac{3 x}{2 \left(x^{2} + 1\right) \operatorname{acot}{\left(x \right)}} + 1 - \frac{3}{8 \left(x^{2} + 1\right) \operatorname{acot}^{2}{\left(x \right)}}}{\left(x^{2} + 1\right)^{2} \sqrt{\operatorname{acot}{\left(x \right)}}}$$