Give the coordinates of the circle's center and its radius. (x−1)^2 +(y+8)^2 =16
a. (-1,8); r=4
b. (1,-8); r=16
c. (1,-8); r=4
d. (-1,8); r=16
e. none of these
A general circle equation is: (x - xc)^2 + (y - yc)^2 = r^2
where (xc, yc) are the centre coordinates and r is the radius.
Compare this with your equation to find the relevant values.