Question

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

Answer 1

We know that

the general equation of a circle is
(x-h)²+(y-k)²=r²
where 
(h,k)----> is the center of a circle
r----------> is the radius

we have
x²+y²=4------------> x²+y²=2²-------> (x-0)²+(y-0)²=2²
then
the center (h,k) is -------------> (0,0)
and radius r=2 units


the answer is the option A.(0, 0)