Problem Solving
A student is drawing a friction drive in which two circular disks are in contact with each other. They are represented by circles in the drawing. The first has a radius of 10.0cm and the second has a radius of 12.0cm. What is the equation of each circle if the origin is at the center of the first circle and the x-axis passes through the center of the second circle?
Solution
First draw a sketch to help visualize the problem. Draw both circles and the x and y axes through the origin.
The equation of the first circle is: x2 + y2 = 102
The second circle is: (x – 22)2 + ( y – 0)2 = 122
or (x – 22)2 + y 2 = 144