A linear parent function is the equation y = x or f(x) = x. A parent function is the simplest equation of a function. Thus, f(x) = x is the simplest of all linear functions and that is the reason why it is called linear parent function.
You can make a table of values to graph this function. See the table below.
|x||y = x|
Here is the graph for this function.
We only show 7 points. However, the graph has infinitely many points.
Therefore, the domain is the set of real numbers and the range is the set of real numbers.