## Precalculus (6th Edition)

$\color{blue}{(x-\sqrt5)^2+(y+\sqrt7)^2=3}$
RECALL: The center-radius form of a circle whose center is at $(h, k)$ and whose radius is $r$ units is: $(x-h)^2+(y-k)^2=r^2$ The given circle has its center at $(\sqrt5, -\sqrt7)$ and has a radius of 15 units. Thus, its equation in center-radius form is : $(x-\sqrt5)^2+(y-(-\sqrt7))^2=(\sqrt3)^2 \\\color{blue}{(x-\sqrt5)^2+(y+\sqrt7)^2=3}$