When do you need to state a domain in your final answer?

Not sure what you are asking.

Domain is all x values .

It can be stated in coordinates (x,y). X is the input. Y is output

It can be stated in Domain Notations such as {x | x ≥ 0}

relating to or denoting a system of numbers and arithmetic based on the number ten, tenth parts, and powers of ten.

it alot will look like this 4.4