What is the largest possible domain for the function

f(x) = sqrt x + sqrt(4 - x^2) ?

sqroot(x)>=0

and

4-x^2>=0

4>=x^2

x>=-2 x<2

Negative numbers does not have a position on the number line.So:

Domain of

f(x)= sqrt(x) + sqrt(4 - x^2)

[-0,2]