Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
%20series%201%20/%20(1%20%2B%20e%20%5E%20(-x))%20at%20x=1
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random