Tangent Connecting 2 Circles

[floridakid]

Find the + tangent line to the circles

x^2 + y^2 = 1


(x-3)^2 + y^2 = 4

So I've determined the derivatives of these circles...how can I use this to solve for the points at which the tangent line touches them?

Any help would be gratefully appreciated.

 

[o_O]

If you're looking for the tangent line that touch BOTH the circles, what would the relationship be between the two derivatives?

 

[galactus]

This exact problem was addressed here:

http://www.mathhelpforum.com/math-help/ ... elp-b.html