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
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)→(8−2,3+4)→(6,7)←new centre of B
to calculate d use the distance formula
∙xd=√(x2−x1)2+(y2−y1)2
let (x1,y1)=(3,1) and (x2,y2)=(6,7)
d=√(6−3)2+(7−1)2=√9+36=√45≈6.71
sum of radii =2+4=6
since sum of radii<d then no overlap
min. distance =d− sum of radii
min. distance =6.71−6=0.71
graph{((x-3)^2+(y-1)^2-4)((x-6)^2+(y-7)^2-16)=0 [-20, 20, -10, 10]}