Question

What is the equation of a circle with a center located at (4, -1) and a radius of 9?

Answer 1

(x-4)^2 + (y+1)^2 = 81

Explanation:

you clearly have internet access and could have very quickly searched for the equation of a circle.

(x-h)^2 + (y-k)^2 = r^2

with (h,k) being the center.

=> (x-4)^2 + (y+1)^2 = 81