Question

The equation for a circle with center (h, k) is (x - h)2 + (y - k)2 = r2. If a circle is modeled by the equation x2 + (y + 6)2 = 100, what is the center of the circle?

A)(0, 6)

B)(6, 0) C)(0, −6) D) (−6, 0)

Answer 1

we know that
the equation of a circle in standard form is
(x-h)²+(y-k)²=r²
where (h,k) is the center
and r is the radius

so
x² + (y + 6)² = 100--------> x² + (y + 6)² = 10²

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

the answer is the option
C)(0, −6)