Circle A has a radius of 5 and a center of (2,7). Circle B has a radius of 4 and a center of (7,3). If circle B is translated by <−1,2>, does it overlap circle A? If not, what is the minimum distance between points on both circles?
1 Answer
Jan 21, 2018
Explanation:
What we have to do here is
compare the distance (d) between the centres of the circles to thesum 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
under the given translation
under a translation <−1,2>
(7,3)→(7−1,3+2)→(6,5)←new centre of B
to calculate d use the distance formula
∙xd=√(x2−x1)2+(y2−y1)2
let (x1,y1)=(2,7) and (x2,y2)=(6,5)
d=√(6−2)2+(5−7)2=√16+4=√20≈4.47
sum of radii =5+4=9
since sum of radii>d then circles overlap
graph{((x-2)^2+(y-7)^2-25)((x-6)^2+(y-5)^2-16)=0 [-20, 20, -10, 10]}