/ 2*x \
| 2*e | x
|1 - --------|*e
| 2*x|
\ 1 + e /
-----------------
2*x
1 + e
/ 2*x 4*x \
| 8*e 8*e | x
|1 - -------- + -----------|*e
| 2*x 2|
| 1 + e / 2*x\ |
\ \1 + e / /
-------------------------------
2*x
1 + e