Question

Part 1: Create a relation of five ordered pairs that is a function. In complete sentences explain why this relation is a function.
Part 2: Create a relation of five ordered pairs that is not a function. In complete sentences explain why this relation is not a function.

Answer 1

Part 1: Let them be of the form (x, f(x))
{(1,2), (2,4), (3,6), (4,8), (5,10)}
This is a function because, firstly, it is a relation, and second, for any x-value, there is only one corresponding f(x)-value.

Part 2:
{(1,0), (-1,0), (0,1), (0,-1), (2,4) }
-This is not a function because there is a left-value, 0, that is mapped (related) to two different right-values.