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.
plot erf(sqrt(pi)/2*x), tanh(x), 2/pi*gd((pi/2)x), x/sqrt(1+x^2), 2/pi*arctan((pi/2)x), x/(1+|x|)
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random