Identifying Functions

Lesson: Input/Output, Independent/Dependent Variables, Doman and Range

​Any set of ordered pairs is a relation. Only certain relations are functions!

​Review from previous lesson

Relations and Functions

​

Each input has one and only one output!

​This table represents a relation that is NOT a function.

Do you know why?






Because the input value -1 is paired with 2 different output values.

Multiple Choice

Is this relation a function?

• Yes

• No

Multiple Choice

Is this relation a function?

• Yes

• No

​In every function, we have the input values, represented by x. A list of all the input values in called the domain.

The output values are represented by y. A list of all the output values is called the range.

​List the members of the domain or the range in order from least to greatest, and do not repeat.

Domain: -4, -2, 2, 3, 6, 11, 19

Range: -3, 1, 2, 5, 12, 16

​Vocabulary

Relation: Any set of ordered pairs

Function: A kind of relation in which each input value has one and only one output value

Domain : All the input values of a function

Range: All the output values of a function

Multiple Choice

A function is represented in this table. The set (-7, -4. -2, 8, 10, 19) lists members of the -

• Domain

• Range

​How to tell if a graph shows a function:

Use the "vertical line" test. (Also called the pencil test.)

​Not a function

​Function

Multiple Choice

Describe this graph.

• This is a function.

• This is not a function.

Multiple Choice

Which one of these is the range for the function shows?

• (1, 2, 3, 4)

• (5, 6, 7, 8)

Open Ended

Describe a function.

Open Ended

Tell how to find the domain of a function.

​Great work!

Now go to Google Classroom to find the IXL skills. You need to do each of them for a grade and it will give you the practice you need.