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.
(X^2+20^2-17^2)/(40X)= (1-((X^2+20^2-13^2)/40X)^2)^(1/2)
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random