Select either relation (if the set is a relation but not a function), function (if the set is both a relation and a function), or neither (if the set is not a relation).
A = {(1, 2) (2, 2) (3, 2) (4, 2)}
pick one??
a relation is a set of ordered pairs and a function is a relation where each domain element is paired with no more than one range element. This set is clearly a relation and it is also a function as each pair has a unique domain element therefore each domain element in the set can only have one range element associated with it.