The distance between a point P and the centre of a circle is 'd'. The given circles radius is r. Then what is the minimum distance between the circle and the point.
d-r
r-d
The circle given is as below
Case 1
There are 2 cases possible. One is when the point is outside the circle and the other when inside it.
When its outside. Shortest distance=d-r
Case 2= When point is inside
In this case the shortest distance is the difference between 'd' and 'r' as you can see from the figure.