$$\frac{3 y_{3}}{9 x^{2} + 1}$$
-54*y3*x
-----------
2
/ 2\
\1 + 9*x /
$$- \frac{54 x y_{3}}{\left(9 x^{2} + 1\right)^{2}}$$
/ 2 \
| 36*x |
54*y3*|-1 + --------|
| 2|
\ 1 + 9*x /
---------------------
2
/ 2\
\1 + 9*x /
$$\frac{54 y_{3} \left(\frac{36 x^{2}}{9 x^{2} + 1} - 1\right)}{\left(9 x^{2} + 1\right)^{2}}$$