Question

Which of the following equations correctly represents a circle centered at the origin with a radius of 5?

A. (x - 5)2 + y2 = 25
B. x2 + y2 = 5
C. x2 + y2 = 25
D. (x - 5)2 + (y - 5)2 = 5

Answer 1

The equation of a circle with center (h,k) and radius = r:
(x-h)^2 + (y-k)^2 = r^2

Answer 2

What values do we use for h, k and r for your problem?