To find the equation of the circle we will use the Distance Formula.
d = sqrt((x_2-x_1)^2 + (y_2-y_1)^2)In this form, the center of the circle is ( x_1, x_2) and d is the circle's radius. Let's label the radius r.
r=sqrt((x_2- x_1)^2+(y_2- y_1)^2)
We have been given that the circle has its center at ( 4, -1) and radius 3. Let's substitute these values into the formula and simplify.