Beginning & Intermediate Algebra
It is not a function because the outputs are not strictly increasing, and 22 and 44 are different
It is not a function because the input x=1x = 1 corresponds to two different outputs (22 and 44)
It is a function because there are exactly three ordered pairs listed, and having three pairs always makes a relation a function
It is a function because each ordered pair is unique, even if inputs repeat, and the uniqueness of the pairs guarantees its status as a function