College Algebra (10th Edition)

$(x-1)^2+y^2=20$
RECALL: The standard equation of a circle whose center is at the origin is: $(x-h)^2+(y-k)^2=r^2$ where $r$ = radius With its center at $(1, 0)$, the tentative equation of the given circle is: $(x-1)^2+(y-0)^2=r^2 \\(x-1)^2+y^2=r^2$ To find the value of $r^2$, substitute the x and y values of the given point into the tentative equation above to obtain: $(x-1)^2+y^2=r^2 \\(-3-1)^2+2^2=r^2 \\(-4)^2+4=r^2 \\16+4=r^2 \\20=r^2$ Therefore, the standard form of the equation of the the given circle is: $(x-1)^2+y^2=20$