11/12/13 Algebra 1 Warm-up 5.1a

1) Solve for :

2) Check whether the given value is a solution to the equation:

NOTES 5.1 & 5.2FUNCTIONS:

ORDERED PAIRS, FUNCTION RULES,

AND GRAPHSTextbook Pgs. 249-260

Vocabulary Relation – two variables (that are related somehow)

Ordered pair –

Domain – all of the possible -values

independent variable, input,

Range – all of the possible -values

dependent variable, output,

Function – for each domain value (), there is

exactly one range value ().

Example 1: Real-life relation:

Write as a set of ordered pairs

Identify the domain and range

Graph the data

Write a rule

Hours 2 5 7 8$ Earned 14 35 49 56

Example 2: Use an equation

with domain: .

Make a table

Identify the range

Plot the points

                  

Example 3: Function or Not?

NOT A FUNCTION – same , different . . . or two points that lie on same vertical line

a) b) c)

d) e.)

Month 2 5 7 8 11  Rain (in)

14 5 0 0 12  

Example 4: Write a function rule Do you see a pattern? Think about… how much is y changing compared to

x? Is y always a certain amount bigger or smaller?

Use a table: Use a graph:

Ex 5: Write a word prob. as a function

You plan to attend up to 5 art lessons that cost $12 each.

Independent Variable? Dependent Variable?

Write the amount you will spend as a function of the number of lessons you will attend.

(Function Rule):

Domain? Range?

Example 6: Analyze a graph

The table shows the profit, (in ten-thousand $) at a toy store each year from 2000 to 2004 as a function of the time in years since 2000.

Graph the data00.95

11.28

22.27

31.76

42.18

* Explain how you know that the graph represents a function

* Describe any trend in the data

Essential Questions:

How do you represent functions as ordered pairs and rules?

If a function contains the ordered pairs and , what is the value of ?

How do you represent functions as graphs?