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.
NSolve[2*Pi*r^3/3-Pi*r^4/4/9.7==1230,r]
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
