1. identify the mapping diagram that represents the given relation and determine whether the relation is a function. {(–3, –6), (–1, –6), (5, –6), (8, –6)}

2. identify the mapping diagram that represents the given relation and determine whether the relation is a function. {(–8, –6), (–5, 2), (–8,1), (7, 3)}

#1) This is a function.
 #2) This is not a function.
(The mapping diagrams are not present to match to these.)

Explanation:
A function is a relation in which each element of the domain is matched to no more than one element of the range; in other words, no x gets mapped to more than 1 y.

In #1, no x is mapped to more than 1 y, so it is a function. However, in #2, -8 is mapped to both -6 and to 1; this x is used more than once, so this is not a function.