Question

(09.04 LC)

Answer 1

Compare  with the standard form of equation of a circle

  (x - a)^2 + (y - b)^2  = r^2   where the center is at (a,b) and radius = r:-
 (x - 9)^2  + (y + 8)^2 = 16

r^1 = 16 giving the  radius = 4   That is a diameter of 8.

and center is at ( 9 , -8)

Correct choice is b.

Answer 2

To get the Center and the Radius you must take out the 2 so divide all terms by 2 gives you     (x-9) +(y+8)=8  therefore the circle is centered at (9,-8) and the radius is 8