What is it?The basic definition of a function is the

relationship between two numbers

You take input values

Use the function

And get some output value

Many LooksFunctions are sometimes represented in many

ways-first data is collected or derived-once collected it is analyzed in a chart, graph,

or table-another way is to draw a diagram-these are called mapping diagrams -they tell what input value corresponds to each

output value

Mapping DiagramsMapping diagrams are one of the visual ways

to present functions

The input values are called the “domain”

And the output values are called the “range”

PointsPoints are one way to look at functions

They are created by using some function rule

Once collected they can be written as ordered pairs which represent some point on a coordinate plane

GraphsYou can create graphical representations of functions

by plotting the points from the data collected

As you can see functions are not always linear

Real-World SituationsA Commute Home is a function

Where the time it takes you to get home depends on the distance needed to travel

It’s a RuleRules are things that tell us what to do!

Functions can be thought of in this same way.

They tell us what to do to do to the input variable in order to get the output

Rules Create ChangeCheck out the change as this car approaches the sign

Now a Function

For whatever variable in this case we…First multiply by threeThen subtract sevenThis will result in a change in whatever input value

73)( xxfWhat’s the “rule”

Lets See it in ActionTake these different inputs

Now look at them

RecapWhat is it?

Relationship between two numbers

RecapHow do you represent it?

Different ways…graphical, diagrams, and points

RecapHow does it work?

Take the input values and use the function rule to get the corresponding output value

CreditsCreated by Jamaar AshleyFor Tech-Ed 6507 Fall 2011

Graphics from “Prentice Hall Algebra 1 Book”Copywrite © Pearson Education, Inc, or its

affiliates