Intro to Functions

Intro to Functions

Ordered Pairs, Tables, Mapping Diagrams

A relation is a set of ordered pairs.

For example:

{ (-3, 2),  (0, 8),  (5, 3) }

The ordered pairs may be displayed as a:

• set

• table

• mapping diagram

A set of ordered pairs may look like this.

(This is a relation.)

A table may look like this.

(This is a relation.)

Open Ended

List 2 ordered pairs represented in this table?

A mapping diagram may look like this.

(This is a relation.)

Open Ended

List all the ordered pairs in this mapping diagram.

Our task is to determine if a relation is a FUNCTION.

We will be asked the question:

Is this relation a Function or NOT a Function?

What is a Function?

To be a function, each input must correspond to exactly one output.

Where do you find the input and output in sets, tables, and mapping diagrams?

Input is "x"

Output is "y"

Multiple Choice

What is the input in this ordered pair?

(4, -2)

• 4

• -2

Multiple Select

What are the inputs in this relation?

{ (-8, 0), (4, -2) }

• -8

• 0

• 4

• -2

Multiple Select

What are the outputs in this relation?

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

• 6

• -1

• 3

• 5

Fill in the Blank

Important to Remember: To be a function, each input must correspond to exactly one ______.

Multiple Choice

{ (8, 9), (3, 0), (-5, 2), (-3, 4), (-2, -3) }

Is this relation a function? Hint: Does each input (x) correspond to exactly one output (y)?

• Function

• Not a Function

Multiple Choice

{ (7, -1), (3, 3), (6, -4), (3, 0), (-1, 6) }

Is this relation a function? Hint: Does each input (x) correspond to exactly one output (y)?

• Function

• Not a Function

Multiple Choice

Is this relation a function? Hint: Does each input (x) correspond to exactly one output (y)?

• Function

• Not a Function

Multiple Choice

Is this relation a function? Hint: Does each input (x) correspond to exactly one output (y)?

• Function

• Not a Function

Multiple Choice

Is this relation a function? Hint: Does each input (x) correspond to exactly one output (y)?

• Function

• Not a Function

Multiple Choice

Is this relation a function? Hint: Does each input (x) correspond to exactly one output (y)?

• Function

• Not a Function

Fill in the Blank

To be a function, each _____ must correspond with exactly one output.

Multiple Choice

Input is the _value.

• x

• y

Multiple Choice

Output is the _value.

• x

• y

Multiple Choice

To be a function, each x-value can have only one y-value.

• true

• false