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.
plot( -k + (2k+12)r - k*r^2 = 0, k=0..500, r=0..1 )
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random