Question

Which set of ordered pairs represents a function?

{(2, –2), (1, 5), (–2, 2), (1, –3), (8, –1)}
{(3, –1), (7, 1), (–6, –1), (9, 1), (2, –1)}
{(6, 8), (5, 2), (–2, –5), (1, –3), (–2, 9)}
{(–3, 1), (6, 3), (–3, 2), (–3, –3), (1, –1)}

Answer 1

The answer is b because no x-value can repeat. 

Answer 2

{(3, –1), (7, 1), (–6, –1), (9, 1), (2, –1)}

Explanation:

A relation is called function if there is only one output value for each input value,

Also, in order pair,

First value represents input and second value represents output.

In relation {(2, –2), (1, 5), (–2, 2), (1, –3), (8, –1)},

There are two output values for 1 which are 5 and -3,

Thus, it can not be a function,

In relation {(3, –1), (7, 1), (–6, –1), (9, 1), (2, –1)}

There is only one output value for each input value.

Thus, it is a function,

In relation {(6, 8), (5, 2), (–2, –5), (1, –3), (–2, 9)}

There are two output values for -2 which are -5 and 9,

Thus, it can not be a function,

In relation {(–3, 1), (6, 3), (–3, 2), (–3, –3), (1, –1)}

There are three output values for -3 which are 1, 2 and -3,

Thus, it can not be a function,