Suppose M(x , y) is a point of the circle of center (6,3) and radius 10 and M is also a point of the y-axis then the coordonates of M should verify these two equations at the same time:
Then
(0-6)² + (y-3)² = 100
then
36 + (y-3)² = 100
then
(y-3)² = 100 - 36
= 64
then
|y-3| = 8
then
y - 3 = 8 or y - 3 = -8
then
y = 11 or y = 5
then the only points that are on the edge of the circle and on y-axis are: