Table of Contents

- 1 What makes an ordered pair not a function?
- 2 Can a set of ordered pairs be a function?
- 3 How do you tell if a set is a function?
- 4 How do you tell if a relation is a function?
- 5 What’s a function and not a function?
- 6 Can a set of five ordered pairs model a function?
- 7 Can a function have two ordered pairs of coordinates?

## What makes an ordered pair not a function?

In order for a relation to be a function, each x must correspond with only one y value. If an x value has more than one y-value associate with it — for example, in the relation {(4, 1), (4,2)}, the x-value of 4 has a y-value of 1 and 2, so this set of ordered pairs is not a function.

## Can a set of ordered pairs be a function?

A function is a set of ordered pairs in which no two different ordered pairs have the same x -coordinate. An equation that produces such a set of ordered pairs defines a function. What is the catch? There can be at most one output for every input.

**Why are some relations not functions?**

If you think of the relationship between two quantities, you can think of this relationship in terms of an input/output machine. If there is only one output for every input, you have a function. If not, you have a relation. Relations have more than one output for at least one input.

**What is not a function?**

If we can draw any vertical line that intersects a graph more than once, then the graph does not define a function because that x value has more than one output. A function has only one output value for each input value.

### How do you tell if a set is a function?

How do you figure out if a relation is a function? You could set up the relation as a table of ordered pairs. Then, test to see if each element in the domain is matched with exactly one element in the range. If so, you have a function!

### How do you tell if a relation is a function?

If each input value leads to only one output value, classify the relationship as a function. If any input value leads to two or more outputs, do not classify the relationship as a function.

**What is a function vs not a function?**

A function is a relation between domain and range such that each value in the domain corresponds to only one value in the range. Relations that are not functions violate this definition. They feature at least one value in the domain that corresponds to two or more values in the range.

**Is a vertical line a function?**

Solution. If any vertical line intersects a graph more than once, the relation represented by the graph is not a function. The third graph does not represent a function because, at most x-values, a vertical line would intersect the graph at more than one point.

## What’s a function and not a function?

## Can a set of five ordered pairs model a function?

That keeps the set of five ordered pairs from modeling a function because it now has two ordered pairs with the same first coordinate 1 . You can made them up by the hundreds. Just put two or more ordered pairs in it that have the same first coordinate, so that it will NOT model a function.

**Which is an example of an ordered pair?**

SOLUTION: Provide an example of at least five ordered pairs that do not model a function. The domain will be any five integers between 0 and 20. The range will be any five integers bet

**Can you make ordered pairs by the hundreds?**

You can made them up by the hundreds. Just put two or more ordered pairs in it that have the same first coordinate, so that it will NOT model a function. You can tell why it doesn’t model a function by telling which first coordinates are the same. Edwin

### Can a function have two ordered pairs of coordinates?

A function can’t have two ordered pairs with the same first coordinate and different second coordinates. Let’s think about what would happen if two such points were on a graph. Notice that if there are two points with the same first coordinate and different second coordinates, we can draw a vertical line through them.