Find the center (h,k) and radius r of the circle.
x^2 +y^2=4
a) (h,k) = (2,2); r=4
b) (h,k) = (0,0); r=4
c) (h,k) = (2,2); r=2
d) (h,k) = (0,0); r=16
The standard formula for a circle is
(x-h)^2 + (y-k)^2= r^2
There is no correct answer listed above.
0,0 r= 2
thanks
To find the center (h,k) and radius r of the circle given by the equation x^2 + y^2 = 4, we can compare it with the standard form of the equation of a circle, (x - h)^2 + (y - k)^2 = r^2.
In the given equation, we can see that the values for h and k are both zero. Thus, we have (x - 0)^2 + (y - 0)^2 = r^2, which simplifies to x^2 + y^2 = r^2.
Comparing this with the equation of the given circle, we can conclude that the center (h,k) is (0,0) and the radius r is 2.
Therefore, the correct answer is option (c) (h,k) = (0,0); r=2.