Question

Which equation could represent a circle with a center located at (11,-5)

Answer 1

The standard equation of a circle is:

$(x-h)^2-(y-k)^2=r^2$ where (h,k) is the center and r is the radius.

We need to make an equation of a circle, whose center is (11,-5) with any radius. Therefore, substitute the value.


$(x-h)^2-(y-k)^2=r^2 \\ (11,-5)=(h,k) \\ (x-11)^2-(y-5)^2=64$

The bolded part is your answer. Since the radius is not given, we can put any value.