State the center and the radius of the circle represented by the equation

Question

(x – 8) 2 + (y + 2)2 = 81

Answer 1

Eq: (x - h)2 + (y - k)^2 = r^2.
C(h , k), r = sqrt(r^2).

(x - 8)^2 + (y + 2)^2 = 81.
C(h , k) = C(8 , -2).
r = sqrt(r^2) = sqrt(81) = 9.