Identifying and Representing Functions

Reteach

A relation is a set of ordered pairs.{(1, 2), (3, 4), (5, 6)}
The input values are the first numbers in each pair. (1,3,5) –domain = x
The outputvalues are the second numbers in each pair. (2,4,6) – range = y
Find the input and output.
1.{(1, 1), (2, 3), (3, 5)} Input = Output =
2.{(6, 2), (5, 3), (4, 8)} Input = Output =
A relation is a functionwheneach input value is paired with only one output value.
The relation below is a function.

Input value 2 is paired with only one output, 5.
Input value 1 is paired with only one output, 1.
Input value 3 is paired with only one output, 1. / The relation below is not a function.

Input value 1 is paired with two outputs,
1 and 3.

Tell whether each relation is a function. Explain how you know.

3.{(1, 5), (3, 7), (6, 5), (9, 8}4.{(1, 2), (1, 8), (3, 6), (4, 8)}

The table below represents a function.

X / Y
6 / 8
5 / 4
4 / 8
8 / 0

Comparing Functions

Find the rate of change and y-intercepts of the linear functions.

1.yx2

rate of change______rate of change______

y-intercept: ______y-intercept:______

Which function has greater rate of change?

2.f(x) 6x 1

rate of change: / f______/ g______
y-intercept: / f______ / g______

Which function has greater rate of change?

3.) On her birthday, Debbiegets a $10 gift card for Dunkin’ Donuts. She spends $2.00 per day to buy a donut after school. Complete the table below to represent this situation:

X(days) / Y(balance)
0 / 10.00
1
2
3

a) Does this function have a positive or negative rate of change? How do you know?

b) What is the rate of change for this function?

c) Graph this function on the grid below. Remember to label your graph.

4) A gorilla at the Philadelphia Zoo recently gave birth to twins. The zoo decided to name the babies Jack and Jill. The zookeeper used a table to track Jill’s weight from birth. His assistant decided to use a graph to track Jack’s weight from birth.

Jill’s weightJack’s weight

Answer the following questions:

a. Which baby weighed more at birth? ______

b. How much more? ______

c. Which baby is growing at a constant rate? ______

d. What is this baby’s rate of change? ______

5. Valerie and Oscar are contestants on the Biggest Loser. Their weight loss progress is shown below.

Valerie’s weight progress is shownOscar’s weight progress is recorded

using the equation below.using the table.

y = -2.5x + 235

Answer the following questions:

a. Who weighed more at the beginning of the show? ______

b. Who is losing weight faster? ______

c. What is Valerie’s rate of change? ______

Analyzing Graph

You have a savings account in a bank. The graphs below show how the amount in your account changes. Write a story about each graph.

1.

______
______
3. Write a story about each graph
/ 2.

______
______