Radio Transmitter Problem

Problem

There is a radio transmitter that is emitting a signal every certain number of hours or minutes. The lenght of time doesn't really matter, but a long time between signals motivates you to come up with a cool mathematical solution.

You have a device that receives the transmission and can tell you the distance you are from the transmission.

So say you're standing @ 0,0 and your receiver tells you that you are 5 units away.

Next you move to 6,8 and you receiver tells you that you are again 5 units away.

Input

x1 y1 r1 x2 y2 r2

Output

One or two x,y values indicating the location of the transmitter.

Also you can certain conditions that yield no results, or infinite results.

Check the code for the details.

Goal

It might be cool to make a canvas-based javascript version of this for the fun of it.