What is a function?

A function is a relationship in which each member of one set is paired with exactly one member of another set.

Let’s look at an example of a

function.

The relationship

between days and weeks.

1 week = 7 days

2 weeks = 14 days

So forth….

If w=weeks then our

expression

is 7w

Step 1:Step 1: Using our data on Using our data on days and weeks, we can days and weeks, we can

write an write an algebraic algebraic expressionexpression to represent to represent

this info.this info.

FUNCTION MACHINESFUNCTION MACHINESUsed to help us remember the next step. You Used to help us remember the next step. You

do not have to show the function machine do not have to show the function machine when completing problems.when completing problems.

Output(Y)Input(X)

7w

Step 2:Step 2: Try some Try some valuesvalues to to determine the output.determine the output.

1 7

Output(Y)Input(X)

7w

2 14

Output(Y)Input(X)

7w

3 21

Output(Y)Input(X)

7w

4 28

Output(Y)Input(X)

7w

Step 3:Step 3: Using the Using the inputsinputs and and outputsoutputs create a create a

function table.function table.Input - X(weeks)

Output - Y(days)

1 7

2 14

3 21

4 28

To Be Continued……To Be Continued……

There is more we can do There is more we can do with functions and function with functions and function

tables! tables!

We will look at that later!We will look at that later!