Answer: The equation of the circle is

Step-by-step explanation: We are given to write the equation of a circle centered at the origin.
We know that the standard equation of a circle with center at the point (g, h) and radius 'r' units is given by

The co-ordinates of the origin are (0, 0).
So, if the center of the circle is at the origin, then we have
(g, h) = (0, 0).
Therefore, from equation (i), we have

Thus, the required equation of the circle is
