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.
solve 1/2*(erf((2+x)/sqrt(2)) - erf((2-x)/sqrt(2))) = 0.4
solve 1/2*(erf((2+x)/sqrt(2)) - erf((2-x)/sqrt(2))) = 0.4
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
