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.
simplify (z+z^(-1))(z^9+z^(-9))(z^11+z^(-11))(z^19+z^(-19)) for z=exp(2pi i/40)
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random