Question

The circle below is centered at the point (8, 4) and has a radius of length 4.

What is its equation?

Answer 1

(x - 8)^2 + (y - 4)^2 = 16.

Explanation:

The standard form can be written as:

(x - a)^2 + (y - b)^2 = r^2 where (a, b) is the center and r = the radius.

So here we have a = 8, b = 4 and r = 4.

(x - 8)^2 + (y - 4)^2 = 4^2

(x - 8)^2 + (y - 4)^2 = 16.