1
----------
/ 2\
| x |
4*|1 + --|
\ 16/
$$\frac{1}{4 \left(\frac{x^{2}}{16} + 1\right)}$$
-x
------------
2
/ 2\
| x |
32*|1 + --|
\ 16/
$$- \frac{x}{32 \left(\frac{x^{2}}{16} + 1\right)^{2}}$$
/ 2 \
| 4*x |
8*|-1 + -------|
| 2|
\ 16 + x /
----------------
2
/ 2\
\16 + x /
$$\frac{8 \left(\frac{4 x^{2}}{x^{2} + 16} - 1\right)}{\left(x^{2} + 16\right)^{2}}$$