Question

what points lies on the circle whose center is at the origin and whose radius is 13?

Answer 1

x^2+y^2=169

Answer 2

by formula
(x-a)^2+(y-b)^2=r^2

Answer 3

(a,b) is center
r= radius

Answer 4

(-5, 12)
(sqrt 13,sqrt13 )
(6, -7)