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.
solve ((x_2 - b*t) - (x_1 - a*t))^2 - ((y_2 - d*t) - (y_1 - c*t))^2 = (r_1 + r_2)^2 for t
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random