A) find the length of each radius (radius of circle m and radius of circle n).

b) what does "point of tangency" mean? and identify the point of tangency.

c) write the equation of the tangent line at this point.

A) From the graph,
.. radius of M is 1
.. radius of N is 3

B) The "point of tangency" is the one point where the circles and tangent line meet. That point is (2, 1).

C) The horizontal tangent line has equation
.. y = 1