Answer:
Domain : [0, ∞) {x | x ≥ 0} (equal to 0 all real numbers greater than or equal to 0).
Step-by-step explanation:
The given function is f(x) = √9x = 3√x
For this function f(x) is defined only if x ≥ 0 because for x < 0 the function is not defined.
f(-x) = 3√(-x) which is not defined.
Therefore domain of this function is domain: [0, ∞) {x | x ≥ 0}