Question

Find the center of the circle whose equation is x2 + y2 = 4.

Answer 1

The general equation of a circle is:
(x−a)^2 + (y−b)^2=r^2

Where (a,b) represent the coordinates of the center and r is the radius.

Here in the equation:

X^2 + y^2 =4

(x−0)^2 + (y−0)^2=2^2

Therefore, the circle has :

center -> (0,0)

Radius -> r=2