The center of a circle is at (-5, 12) and it has a radius of 16. What is the equation of the circle?

(x - 5) 2 + (y + 12) 2 = 256

(x - 5) 2 + (y + 12) 2 = 4

(x + 5) 2 + (y - 12) 2 = 4

(x + 5) 2 + (y - 12) 2 = 256

Asking the Math Gods ...

Standard equation of a circle with a center at (-5,12) and radius 16 is:

(x+5) 2 + (y-12) 2 = 256

Explanation

The equation of a circle with center at (h, k) and a radius of r is:

(x-h) 2 + (y-k) 2 = r2

In this example h=-5, k=12 and r=16, so after substituting into above formula we get:

(x - (-5)) 2 + (y-12) 2 (x+5) 2 + (y-12) 2 = 162 = 256