Question

The equation for a circle with center (h, k) is (x - h)^2 + (y - k)^2 = r^2. If a circle is modeled by the equation x^2 + (y + 6)^2 = 100, what is the center of the circle?

Answer 1

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

x^2 + (y + 6)^2 = 100

we can rewrite this as

(x-0)^2 + (y - -6)^2 = 10^2

the center is (0,-6) and the radius is 10