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

1 Answer
Apr 14, 2016

no overlap , d ≈ 3.32

Explanation:

A translation does not change the shape of a figure , only it's position.

Under a translation of #((-2),(5))#

centre of B(5 , 3) → (5-2 , 3+5) → (3 , 8)

Require to calculate the distance between the centres of A and B , using the #color(blue)" distance formula " #

#color(red)(|bar(ul(color(white)(a/a)color(black)( d = sqrt((x_2 - x_1)^2 + (y_2 - y_1)^2))color(white)(a/a)|)))#
where # (x_1,y_1)" and " (x_2,y_2)" are 2 coordinate points "#

let # (x_1,y_1)=(1,2)" and " (x_2,y_2)=(3,8)#

#d = sqrt((3-1)^2 + (8-2)^2)=sqrt(4+36)=sqrt40 ≈ 6.32 #

now radius of A + radius of B = 1+2 =3

Since sum of radii < distance between centres , no overlap.

and distance between circles = 6.32 - 3 = 3.32