Which of the following lists of ordered pairs is a function?

A. [tex]$(1,2),(4,0),(3,5),(4,3)$[/tex]
B. [tex]$(2,5),(3,6),(6,9)$[/tex]
C. [tex]$(2,5),(3,6),(2,1)$[/tex]
D. [tex]$(-1,2),(2,3),(3,1),(2,5)$[/tex]



Answer :

To determine which of the given lists of ordered pairs is a function, we need to recall the definition of a function. A function is a relation where each input (or domain value) is associated with exactly one output (or range value). In other words, no x-value (input) can be repeated with different y-values (outputs).

Let's examine each list of ordered pairs step by step:

### List A: [tex]\((1,2), (4,0), (3,5), (4,3)\)[/tex]

- The x-values are: 1, 4, 3, 4
- The x-value 4 is repeated with different y-values (0 and 3).

Since the x-value 4 is repeated with different y-values, List A is not a function.

### List B: [tex]\((2,5), (3,6), (6,9)\)[/tex]

- The x-values are: 2, 3, 6
- None of the x-values are repeated.

Since none of the x-values are repeated, List B is a function.

### List C: [tex]\((2,5), (3,6), (2,1)\)[/tex]

- The x-values are: 2, 3, 2
- The x-value 2 is repeated with different y-values (5 and 1).

Since the x-value 2 is repeated with different y-values, List C is not a function.

### List D: [tex]\((-1,2), (2,3), (3,1), (2,5)\)[/tex]

- The x-values are: -1, 2, 3, 2
- The x-value 2 is repeated with different y-values (3 and 5).

Since the x-value 2 is repeated with different y-values, List D is not a function.

### Conclusion

After examining each list, List B was determined to be the only one where none of the x-values are repeated with different y-values. Therefore, List B:

[tex]\((2,5), (3,6), (6,9)\)[/tex]

is a function. The results are:
- List A: Not a function
- List B: Function
- List C: Not a function
- List D: Not a function

Thus, List B is the answer.