plot [-((231.85/4.5344)*r^3/x -(231.85/4.5344)*r^2)+(x^2/2-r^2/2)=0.5] for r=0 to 0.025 and x= 0.9 to 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.