What is the equation for circle?

Answer 1

x^2+y^2=r^2 is a circle centered at the origin with radius r.

To move it to location (h,k)

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

For example:

(h , k ) = (2 , - 4) and radius is 5 Then, (x - 2)^2 + (y - (- 4))^2 = 5^2 or (x - 2)^2 + (y + 4)^2 = 25