7
--------------
2
1 + (7*x + 1)
$$\frac{7}{\left(7 x + 1\right)^{2} + 1}$$
-98*(1 + 7*x)
-----------------
2
/ 2\
\1 + (1 + 7*x) /
$$- \frac{686 x + 98}{\left(\left(7 x + 1\right)^{2} + 1\right)^{2}}$$
/ 2 \
| 4*(1 + 7*x) |
686*|-1 + --------------|
| 2|
\ 1 + (1 + 7*x) /
-------------------------
2
/ 2\
\1 + (1 + 7*x) /
$$\frac{\frac{2744 \left(7 x + 1\right)^{2}}{\left(7 x + 1\right)^{2} + 1} - 686}{\left(\left(7 x + 1\right)^{2} + 1\right)^{2}}$$