Calculus: Early Transcendentals (2nd Edition)

$(x-2)^2 + (y-3)^2 = 25$
An equation of a circle would represent all sets of all points $R$ units away from the coordinate $(a, b)$, where $R$ is the radius and the center is at $(a,b)$. Equation of a circle: $(x-a)^2 + (y-b)^2 = R^2$ Using $R=5$ and the center to be $(2,3):$ $(x-2)^2 + (y-3)^2 = 25$