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

1 Answer
Sep 13, 2017

"circles overlap"circles overlap

Explanation:

What we have to do here is color(blue)"compare"compare the distance ( d) between the centres of the circles to the color(blue)"sum of radii"sum of radii

• " if sum of radii ">d" then circles overlap" if sum of radii >d then circles overlap

• " if sum of radii " < d" then no 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 which does not change the shape of the circle only it's position.

"under a translation "((2),(-1))

(1,4)to(3,3)larrcolor(red)" new centre of B"

"since "(5,3)" and "(3,3)" have the same y-coordinate then"
"d is the difference of the x-coordinates"

rArrd=5-3=2

"sum of radii "=4+3=7

"since sum of radii ">d" then circles overlap"
graph{((x-5)^2+(y-3)^2-16)((x-3)^2+(y-3)^2-9)=0 [-20, 20, -10, 10]}