Question

Which is an equation of the circle with a radius of 9 units and center at
(–4, 2)?
A(x − 9)2 + (y + 4)2 = 4

B) (x − 4)2 + (y + 2)2 = 81

C) (x + 4)2 + (y − 2)2 = 81

D) (x − 2)2 + (y + 4)2 = 81

Answer 1

the answer is C)

Answer 2

Because the formula of Circle Equation is : \[(x-x0)^2+(y-y0)^2=r^2\]
while the point \[(x0,y0) \] is the Center and \[r\] is the radius