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