center: $(0, 0)$; radius = 3 units Refer to the image below for the graph.
Work Step by Step
RECALL: The circle $x^2+y^2=r^2$ has its center at $(0, 0)$ and a radius of $r$ units. The given circle can be written as $x^2+y^2=3^2$. This equation is in the same form as the one in the recall part above so its center is at $(0, 0)$ and its radius is $3$. Plot the points that are: 3 units above the center: $(0, 3)$ 3 units below the center: $(0, -3)$ 3 units to the left of the center: $(-3, 0)$ 3 units to the right of the center: $(3, 0)$ Then, connect the points using a curve to form a circle. (refer to the attached image in the answer part above)