Try solving this quadratic equation for the values of r that make it true.
Remember, you'll need to set this equation equal to 0 before you can use this
quadratic formula. Notice too, that instead of having the variable x, we have
the variable r. That's okay though, because it isn't the variable that makes
something quadratic. It's the square on the variable. So try rearranging this
equation, and then, write your final solutions here. Good luck.
