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.
UPGRADE TO PRO
APPS
TOUR
solve sqrt (Pi^2*(1-(2*Pi*f)^2/3e+05^2))=3
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random