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