$$- \frac{4 x^{3}}{x^{8} + 1}$$
/ 8 \
2 | 8*x |
4*x *|-3 + ------|
| 8|
\ 1 + x /
------------------
8
1 + x $$\frac{4 x^{2}}{x^{8} + 1} \left(\frac{8 x^{8}}{x^{8} + 1} - 3\right)$$
/ 16 8 \
| 64*x 52*x |
8*x*|-3 - --------- + ------|
| 2 8|
| / 8\ 1 + x |
\ \1 + x / /
-----------------------------
8
1 + x $$\frac{8 x}{x^{8} + 1} \left(- \frac{64 x^{16}}{\left(x^{8} + 1\right)^{2}} + \frac{52 x^{8}}{x^{8} + 1} - 3\right)$$