The domain is the possible set of x-values of the function.
As you can see the line starts at the origin (0,0) and the other endpoint of the line has an arrow, which means that it can stretch indefinitely. So the domain is all positive real numbers, you can express it as:
[tex]x\ge0[/tex]
The range is the possible set of y-value of the function.
As well as happened with the domain, the range of this line starts at y=0 and continues indefinitely. You can express the range as:
[tex]y\ge0[/tex]
