x^2=y^2=9 that is the answer for the math problem
[tex]\textit{equation of a circle}\\\\ (x- h)^2+(y- k)^2= r^2 \qquad center~~\stackrel{origin}{(\stackrel{0}{ h},\stackrel{0}{ k})}\qquad \qquad radius=\stackrel{3}{ r} \\\\\\ (x-0)^2+(y-0)^2=3^2\implies x^2+y^2=9[/tex]
