Explanation
We are required to graph the function below and determine its domain and range.

This is achieved thus:
We can graph the function by obtaining two coordinates as follows:

Therefore, the graph becomes:
The graph is a linear graph, hence, the domain and the range are all real numbers.
Hence. the answer is:
Domain: (- ∞, ∞)
Range: (- ∞, ∞)
Yes, it is a function.