Circle A has a radius of 1 1 and a center of (1 ,2 )(1,2). Circle B has a radius of 4 4 and a center of (5 ,3 )(5,3). If circle B is translated by <-2 ,5 ><2,5>, does it overlap circle A? If not, what is the minimum distance between points on both circles?

1 Answer
Jul 21, 2017

The circles do not overlap. The minimum distance is =1.3=1.3

Explanation:

The sum of the radii of the circles is

r_A+r_B=1+4=5rA+rB=1+4=5

The center of circle BB after translation is

=(5,3)+<-2,5>=(3,8)=(5,3)+<2,5(3,8)

The distance between the centers is

d=sqrt((3-1)^2+(8-2)^2)=sqrt(4+36)=sqrt40=6.3d=(31)2+(82)2=4+36=40=6.3

As

d>r_A+r_Bd>rA+rB

The circles do not overlap.

The minimum distance is

=d-(r_A+r_B)=6.3-5=1.3=d(rA+rB)=6.35=1.3

graph{((x-1)^2+(y-2)^2-1)((x-3)^2+(y-8)^2-16)=0 [-12.58, 15.9, -3, 11.24]}