Answer:
The smallest number that is in the domain of fog is 3
Step-by-step explanation:
f(x) = [tex]\sqrt{8x}[/tex] (as corrected in comments)
g(x) = x-3
we need to find fog = f(g(x))
For finding f(g(x)) we put the value of g(x) inside the f(x)
f(g(x))=[tex]\sqrt{8(x-3)}[/tex]
The domain of this function is x ≥ 3
because if value of x is less than 3 than the result would be negative and we know √f(x) ≥ 0
So, the smallest number that is in the domain of fog is 3