ANSWER
y = √2x
Step-by-step explanation
The domain is all the posible x-values where the function exists (has a y-value).
The domain of y=2√x is x ≥ 0, because what's inside the square root cannot be negative.
From these options two are cubic roots, and for those kind of functions it can be negative values.
The other two options are square roots as well. The domain of this function is: