Question

Determine if the following relations represent a function

1. {(-1, -2), (0, -2), (1, -2), (2, -2)}
2. {(1, 0), (1,1), (1, 2), (1, -2)}

Answer 1

1) Yes, because each value of x maps onto only one value of y.

2) No, because the x-value of 1 maps onto 4 different y values.

Answer 2

1. yes, a function.
2. no, not a function.

Explanation:

You want to know if the given sets of ordered pairs represent a function.

Function

A function is a relation that maps an input value to a single output value. On a graph, this means no two points are vertically aligned. For a table or set of ordered pairs, it means no input (x) value is repeated.

1.

The input (x) values are {-1, 0, 1, 2} with no repeats. This relation is a function.

2.

The input values are {1, 1, 1, 1} with repeats. This relation is not a function.