Circle A has a center at #(1 ,-4 )# and a radius of #2 #. Circle B has a center at #(9 ,3 )# and a radius of #5 #. Do the circles overlap? If not what is the smallest distance between them?

1 Answer
Feb 16, 2016

The circles do not overlap;
they are separated by a minimum distance of #1.6# units

Explanation:

The distance between the centers of the circles:
#color(white)("XXX")d=sqrt((1-9)^2+(-4-3)^2) =sqrt(113)~~10.6#

Circle A covers 2 (units) of the distance along the line segment from the center of A to the center of B.

Circle B covers 5 (units) of the distance along the line segment form the center of B to the center of A.

A distance of
#color(white)("XXX")10.6 -(2+7)=1.6# along the line segment joining the two centers
is not covered by either circle.