Circle A has a radius of 2 and a center at (3,1). Circle B has a radius of 4 and a center at (8,3). If circle B is translated by <2,4>, does it overlap circle A? If not, what is the minimum distance between points on both circles?

1 Answer
Mar 1, 2018

no overlap 0.71 units

Explanation:

What we have to do here is to compare the
distance (d) between the centres with the sum of radii

if sum of radii>d then circles overlap

if sum of radii<d then no overlap

Before calculating d we require to find the centre of B
under the given translation

under the translation <2,4>

(8,3)(82,3+4)(6,7)new centre of B

to calculate d use the distance formula

xd=(x2x1)2+(y2y1)2

let (x1,y1)=(3,1) and (x2,y2)=(6,7)

d=(63)2+(71)2=9+36=456.71

sum of radii =2+4=6

since sum of radii<d then no overlap

min. distance =d sum of radii

min. distance =6.716=0.71
graph{((x-3)^2+(y-1)^2-4)((x-6)^2+(y-7)^2-16)=0 [-20, 20, -10, 10]}