Answer
$x^2+y^2=\dfrac{49}{4}$
Work Step by Step
Using the standard form of the equation of circles which is given by $(x-h)^2+(y-k)^2=r^2$ where the center is $(h,k)$ and radius $r$, then the equation of the circle with the given center at $
(0,0)
$ and the given radius is $
\dfrac{7}{2}
$ is
\begin{array}{l}
\left( x-0 \right)^2+\left( y-0 \right)^2=\left( \dfrac{7}{2} \right)^2\\\\
x^2+y^2=\dfrac{49}{4}
.\end{array}
