f(x)= 4-x^2 and g(x)= sqrt (x)

find the implied domain of fg(x)
fg(x)= f(sqrt(x))
fg(x)= 4-(sqrt(x))^2
fg(x)=4-(sqrt x)(sqrt x)
fg(x)=4-x
domain= (x:x=all real numbers)
Am I correct?

Are you trying to find f of g of x or f*g of x?

f of g of x

Yes, you are correct! The implied domain of fg(x) is indeed all real numbers. When we find the composition fg(x), we substitute sqrt(x) into f(x). Since the domain of sqrt(x) is non-negative real numbers (x ≥ 0), and there are no restrictions on the domain of f(x) (which is all real numbers), the implied domain of fg(x) is the intersection of the two domains, which is all real numbers. So, the domain of fg(x) is (x: x = all real numbers). Well done!