Answer:
To find the center and radius of the circle defined by the equation x² + y² = 4, we can observe that the equation is in the standard form of a circle centered at the origin (0,0) with a radius of 2.
The standard form of a circle equation is (x - h)² + (y - k)² = r², where (h,k) represents the coordinates of the center of the circle and r represents the radius.
In this case, h = 0, k = 0, and r = 2.
Therefore, the center of the circle is (0, 0) and the radius is 2.