Hello!
There are endless possibilities to name an example of a function with the domain and range as the set of all real numbers. A type of function that always has the domain and range as the set of all real numbers is linear functions. Some examples of linear function with the domain (-∞, +∞), and a range (-∞, +∞), are as follows:
y = x
y = 5/3x - 9
y = 4x + 3
However, the possibilities are endless. Those three examples are just some of them!