Question 474601
an equation of the circle with center (a,b) and radius r
{{{(x-a)^2+(y-b)^2=r^2}}}
a diameter of a circle is 6, the the radius {{{r=d/2=6/2=3}}}
an equation of the circle with center (0,3) and radius 3
{{{(x-0)^2+(y-3)^2=3^2}}}
{{{x^2+(y-3)^2=9}}}