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.
\int_{-640}^{640}\sqrt{1+\left(\frac{640}{663}\frac{e^{x/1326}-e^{-x/1326}}{2}\right)^2}dx
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random