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 (((n/2)*(1/cos(Pi/n))^2*sin(2*Pi/n))/Pi) from n=7 to n=35
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random