Circle A has a radius of 6 and a center of (2,5). Circle B has a radius of 3 and a center of (1,7). If circle B is translated by <3,1>, does it overlap circle A? If not, what is the minimum distance between points on both circles?
1 Answer
Jul 2, 2018
Explanation:
What we have to do here is compare the distance d
between the centres of the circles 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 <3,1>
(1,7)→(1+3,7+1)→(4,8)←new centre of B
to calculate d use the distance formula
∙xd=√(x2−x1)2+(y2−y1)2
let (x1,y1)=(2,5) and (x2,y2)=(4,8)
d=√(4−2)2+(8−5)2=√4+9=√13≈3.61
sum of radii =6+3=9
since sum of radii>d then circles overlap
graph{((x-2)^2+(y-5)^2-36)((x-4)^2+(y-8)^2-9)=0 [-40, 40, -20, 20]}