Question

What is the center of the circle given by the equation below?

A. (-4 , -8)
B. (4 , -8)
C. (4 , 8)
D. (-4 , 8)

Answer 1

Answer:

C:  (4, 8)

Step-by-step explanation:

Rewrite the given equation x² - 8x = -y² + 16y - 44 in std. form:

                                              x² - 8x + 16 - 16 + y² - 16y + 64 =  64 - 44,  or

                                                 (x - 4)²  + (y - 8)² = 64 - 44 + 16

         Comparing this to            (x - h)² + (y - k)² = 6²

we see that h = 4 and k = 8.  The radius is 6.  The center is at (4, 8) (Answer C).