Answer:
If the x-6 is all under the sqrt, the last answer is right:
6<= x <= infinity
If only x is under the sqrt and - 6 is NOT under the sqrt, then:
0 <= x <= infinity is the correct answer.
Step-by-step explanation:
You can look at the equation and or graph to determine the domain of a function. The domain is all the x's that may go into the equation or all the x's on the graph of the function. Inside of a squareroot symbol the number inside there must be positive. While considering the equation, only x's that keep that inside positive can be used.
For sqrt(x-6), x has to be 6 or bigger.
For sqrt(x) - 6, x has to be 0 or bigger.