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.
arg(cos(-pi/4) + i sin(-pi/4))
arg(cos(-pi/4) + i sin(-pi/4))
Natural Language
Math Input
Extended Keyboard