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.
((2r+4000)^2 - (2r+2000)^2)/((2r+2000)^2 - 3r^2) at r = 1000
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random