$$- \frac{9}{81 x^{2} + 1}$$
1458*x
------------
2
/ 2\
\1 + 81*x /
$$\frac{1458 x}{\left(81 x^{2} + 1\right)^{2}}$$
/ 2 \
| 324*x |
1458*|1 - ---------|
| 2|
\ 1 + 81*x /
--------------------
2
/ 2\
\1 + 81*x /
$$\frac{- \frac{472392 x^{2}}{81 x^{2} + 1} + 1458}{\left(81 x^{2} + 1\right)^{2}}$$