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.
(integrate x^2 exp(-x^2/2), x = -a to a) / (integrate exp(-x^2/2), x=-a to a
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random