Question

The equation of two circles are known, circle A’s equation is (x-3)^2+(y+4)^2=9 and circle B’s equation is (x+4)^2+(y+12)^2=8.

What is the radius of circle A and the radius of circle B.

Answer 1

Explanation:

The circles are written in standard form. The standard form squares the radius on the right hand side.

Circle A

radius = sqrt(9)

radius = 3

Circle B

radius = sqrt(8)

radius = sqrt(2 * 2 * 2)

radius = 2 sqrt(2)