1) the small circle inside the big circle or the small circle is to the opposite of the big circle: slope = infinity 2) the small circle to the left of the big circle: if center for the small circle is (4, 4), then the center for the big circle is (a, 6), and (a-4)^2 + (6-4)^2 = 10^2. Slope = (1/24)^(1/2) 3) small circle to the right of the big circle: if center for the big circle is (6, 6), then the center for the small circle is (b, 4), and (b-6)^2 + (4-6)^2 = 10^2. Slope = -(1/24)^(1/2)