Circle C lies on the coordinate plane with its center at (2,−16).

Point A(2,−13) lies on circle C.
Which equation verifies that the point P(−1,−16) lies on circle C?
a. (2−16)^2+(2−13)^2=(2−16)^2+(−1−16)^2
b. (2+1)^2+(−16+16)^2=(2−2)^2+(−16+13)^2
c. (2+16)^2+(−1+16)^2=(2+2)^2+(−16−13)^2
d. (2−1)^2+(−16−16)^2=(2+2)^2+(−16−13)^2

3 answers

circle with centre (2,-16) is
(x-2)^2 + (y+16)^2 = r^2
but A(2,−13) lies on it, so
0^2 + 3^2 = r^2 = 9

equation : (x - 2)^2 + (y + 16)^2 = 9

so to see if P(−1,−16) lies on it, I would try to show LS = RS
LS = (-1 - 2)^2 + (-16+16)^2
= 9 + 0 = 9
= RS , then yes, point P lies on the circle

Don't understand why they would want to make it look so complicated

it’s b

whats the answer.