Here when x<0, the function is undefined (complex) in real range.

So the domain of the function is x ≥ 0.

For this one – the graph simply does not exist in the negative domain.

## Which functions have a domain of all real numbers?

F is a rational function. Its denominator term is (2×2 – 2). Therefore, the domain is found by setting this term equal to zero. The domain for this function is all real numbers except for x=-1 and x=1.

## Is the domain always all real numbers?

Domain is all real numbers except 0. Since division by 0 is undefined, (x-3) cannot be 0, and x cannot be 3. Domain is all real numbers except 3. Since the square root of any number less than 0 is undefined, (x+5) must be equal to or greater than zero.

## How do you know if something is all real numbers?

The Real Number Line

Points to the right are positive, and points to the left are negative. Any point on the line is a Real Number: The numbers could be whole (like 7) or rational (like 20/9)