Question

What is the equation of a circle with a center at (1, 1) and a radius of 5?

Answer 1

Supposing the center of the circle is at (h,k) and that the radius is r, the standard equation for the circle is (x-h)^2 + (y-k)^2 = r^2.

If the center is at (1,1) and the radius of the circle is 5, then

(x-1)^2 + (y-1)^2 = 5^2 (answer)