Circle A has a radius of 2 and a center at (3,6). Circle B has a radius of 4 and a center at (2,3). If circle B is translated by <2,1>, does it overlap circle A? If not, what is the minimum distance between points on both circles?

1 Answer
Jul 15, 2018

circles overlap

Explanation:

What we have to do here is compare the distance (d)
between the centres 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 new
centre of B under the given translation

under the translation <2,1>

B(2,3)(22,3+1)(0,4)new centre of B

to calculate d use the distance formula

xd=(x2x1)2+(y2y1)2

let (x1,y1)=(3,6) and (x2,y2)=(0,4)

d=(03)2+(46)2=9+4=133.61

sum of radii =2+4=6

since sum of radii>d then circles overlap
graph{((x-3)^2+(y-6)^2-4)((x-0)^2+(y-4)^2-16)=0 [-20, 20, -10, 10]}