Answer:
all real numbers greater than or equal to 0
Explanation:
The domain of the function is whatever the input (in this case, x) can be. As you cannot take the square root of a negative number, x cannot be negative. Because you can take the square root of 0 (which is 0), x can be anything postive or 0, meaning anything greather than or equal to 0. The domain is all real numbers greater than or equal to 0.