Question

Is the relation a function? (-11,3),(-8,12), (2,6), (5,4), (14,6), (16,4) Why or why not.

Answer 1

A relation is a set of points.

If a relation is a function, then any value of x in the relation can be paired with exactly one value of y for that x value.

-11 is paired with the y-value of 3.

Look at the remaining ordered pairs.

Do you see -11 used again as an x-value and paired with a different value of y from 3?

Answer 2

@Directrix No, 11 is not used again.

Answer 3

Correct.

Do you see any value of x that is paired with two different y-values?

Answer 4

Function: A function is a set of ordered pairs in which each x-element has only ONE y-element associated with it.

Answer 5

Tip:

{(1,2), (2, 4), (3, 5), (2, 6), (1, -3)}

is NOT a function because of this: (1,2) ; (1, -3)

The x of 1 is paired with two different y values.

Answer 6

@rowanwhitethorn

Do you think the relation you posted is a function?

Answer 7

It is different with vice versa right? One y value can be in two different x values.

Answer 8

So, it's not a function, correct?

Answer 9

@rowanwhitethorn

If it is not a function, then the same x is paired with two different y values.

Which x value in the relation is paired with two different y values?

(-11,3),(-8,12), (2,6), (5,4), (14,6), (16,4)

Answer 10

2 is paired with 6
14 is paired with 6.

But, that is not what we are looking for.

We are looking to see if there is a same x paired with different y values.

Answer 11

@rowanwhitethorn

>So, it's not a function, correct?

Try again.

Answer 12

@Directrix Is this correct: The relation is a function because the x-coordinate is not paired with any y-values.

Answer 13

Almost but not quite correct.

The relation is a function because each x-element has only ONE y-element associated with it.

Answer 14

@rowanwhitethorn ^^^^^

Answer 15

@Directrix Okay, thank you so much for your help! I've been stuck on this question all night.

Answer 16

You are welcome.