Answer:
The general form of the equation of a circle is: (x – h)2 + (y – k)2 = r2
(h, k) is the centre of the circle. r is the radius of the circle.
Substituting the centre and radius of the circle in he general form,
(x – 0)2 + (y – 0)2 = 42
x2 + y2 = 16
The equation of a circle with . Centre at the origin and radius 4 is,
x2 + y2 = 16