Arithmetic sequences are written in a general format.
a_n=a_1+(n-1)d
In this formula, n represents the x-coordinates on a graph and a_n represents the y-coordinates. Let's think about whether the domain and range are continuous or discrete separately.
Domain
The domain corresponds to the possible inputs of a function. In the case of arithmetic functions, the inputs n are the numbers of the terms, where the first term is n=1, the second term is n=2, the third term is n=3, and so on. Therefore, the inputs can only be positive, integer values, so the domain is discrete.
Range
Because the domain is discrete and we can only substitute positive integers for n, the function will only give outputs corresponding to those specific inputs. This means that the range is also discrete.
