$$- \frac{1}{\sinh^{2}{\left (x \right )}}$$
2*cosh(x)
---------
3
sinh (x)
$$\frac{2 \cosh{\left (x \right )}}{\sinh^{3}{\left (x \right )}}$$
/ 2 \
| 3*cosh (x)|
2*|1 - ----------|
| 2 |
\ sinh (x) /
------------------
2
sinh (x)
$$\frac{1}{\sinh^{2}{\left (x \right )}} \left(2 - \frac{6 \cosh^{2}{\left (x \right )}}{\sinh^{2}{\left (x \right )}}\right)$$