Question

Help: Justify why one relation is a function and why the other is not. Relation 1:

(1,2) (2,4) (3,6) (4,8)


Relation 2:  (1, 3), (4, 2), (7, 1), (4,

Answer 1

Relation 1 is a function because we don't have any repeated x values. Each input goes to exactly one output.

On the other hand, relation 2 is not a function because x = 4 repeats itself. The input x = 4 leads to more than one output.