(r^2+x^2)(s^2+(d-x)^2)=(D^2-r^2-x^2-s^2-(d-x)^2)^2

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.