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