The mapping diagram above does not represent a function since there is at least one element in set A (8) mapping to multiple elements in set B (-1 and 5), violating the definition of a function where each element in the domain maps to a unique element in the codomain.
To determine if the mapping represents a function, we need to check if each element in set A is associated with only one element in set B. In this case:
1. Arrow from 2 in set A to -1 in set B: Function is valid.
2. Arrow from 3 in set A to -2 in set B: Function is valid.
3. Arrow from 8 in set A to -1 in set B: Not valid (multiple elements in set A map to the same element in set B).
4. Arrow from 8 in set A to 5 in set B: Valid (since we already identified the first arrow from 8 to -1 as not valid, this doesn't matter).
Since there is at least one instance where an element in set A maps to more than one element in set B, the mapping does not represent a function.