Circle A has a radius of 3 and a center at (1,2). Circle B has a radius of 5 and a center at (3,7). 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
Jun 3, 2018
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 <2,4>
(3,7)→(3+2,7+4)→(5,11)←new centre of B
to calculate d use the distance formula
∙xd=√(x2−x1)2+(y2−y1)2
let (x1,y1)=(1,2) and (x2,y2)=(5,11)
d=√(5−1)2+(11−2)2=√16+81=√117≈10.82
sum of radii =3+5=8
since sum of radii<d then no overlap
minimum distance =d− sum of radii
××××××x=10.82−8=2.82
graph{((x-1)^2+(y-2)^2-9)((x-5)^2+(y-11)^2-25)=0 [-20, 20, -10, 10]}