The second derivative
[src]
9
3718*atan (7 + 13*x)*(5 - (7 + 13*x)*atan(7 + 13*x))
----------------------------------------------------
2
/ 2\
\1 + (7 + 13*x) /
$$\frac{3718 \left(- \left(13 x + 7\right) \operatorname{atan}{\left(13 x + 7 \right)} + 5\right) \operatorname{atan}^{9}{\left(13 x + 7 \right)}}{\left(\left(13 x + 7\right)^{2} + 1\right)^{2}}$$
The third derivative
[src]
/ 2 2 \
8 | 2 45 30*(7 + 13*x)*atan(7 + 13*x) 4*(7 + 13*x) *atan (7 + 13*x)|
48334*atan (7 + 13*x)*|- atan (7 + 13*x) + --------------- - ---------------------------- + -----------------------------|
| 2 2 2 |
\ 1 + (7 + 13*x) 1 + (7 + 13*x) 1 + (7 + 13*x) /
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2
/ 2\
\1 + (7 + 13*x) /
$$\frac{48334 \left(\frac{4 \left(13 x + 7\right)^{2} \operatorname{atan}^{2}{\left(13 x + 7 \right)}}{\left(13 x + 7\right)^{2} + 1} - \frac{30 \left(13 x + 7\right) \operatorname{atan}{\left(13 x + 7 \right)}}{\left(13 x + 7\right)^{2} + 1} - \operatorname{atan}^{2}{\left(13 x + 7 \right)} + \frac{45}{\left(13 x + 7\right)^{2} + 1}\right) \operatorname{atan}^{8}{\left(13 x + 7 \right)}}{\left(\left(13 x + 7\right)^{2} + 1\right)^{2}}$$