The center of a circle is at (2, −5) and its radius is 12. What is the equation of the circle? a) (x−2)2+(y+5)2=24 b) (x+2)2+(y−5)2=24 c) (x+2)2+(y−5)2=144 d) (x−2)2+(y+5)2=144
It's d. The equation for a circle is [tex](x-h) ^{2} +(y-k) ^{2} = r^{2} [/tex] where h is the x coordinate of the circle's center and k is the y coordinate of the circle's center. The radius of 2 then is squared to get 144.