Question

circle A has equation (x+5)^2+y^2=169. The diameter of circle B is one fourth as long as the diameter of circle A. What is the radius of circle B?

Answer 1

the general form for a circle is

\[(x -h)^2 + (y - k)^2 = r^2\]

in your question the centre is (-5, 0) so h = -5 and k = 0

and r^2 = 169

to find the radius, take the square root.

to find the radius of circle B divide your radius by 4

Answer 2

divide 169 by 4 or do I divide the square root of 169's square root by 4? @campbell_st

Answer 3

no divide the square root of 169 by 4

the square root of 169 is the radius of circle A

Answer 4

okay thank you so much! @campbell_st