Circle A has a radius of 4 and a center at (7,2). Circle B has a radius of 3 and a center at (4,5). If circle B is translated by <3,4>, does it overlap circle A? If not, what is the minimum distance between points on both circles?

1 Answer
Feb 17, 2018

no overlap ,2.22

Explanation:

what we have to do here is compare the distance (d)
to the sum of the 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 a translation <3,4>

(4,5)(43,5+4)(1,9)new centre of B

to calculate d use the distance formula

xd=(x2x1)2+(y2y1)2

let (x1,y1)=(7,2) and (x2,y2)=(1,9)

d=(17)2+(92)2=36+499.22

sum of radii =4+3=7

since sum of radii<d then no overlap

min. distance =dsum of radii

min. distance =9.227=2.22
graph{((x-7)^2+(y-2)^2-16)((x-1)^2+(y-9)^2-9)=0 [-40, 40, -20, 20]}