1/(10+2 sqrt(5)) = (1 + x^2)/(x^2 -1 + 24.36881039 + 2x sqrt(24.36881039 -1))

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.