Alg1 Lesson 1.11 Function Notation in Context

Lesson 1.11: Function

Notation in Context

Obj: 2C, 3C, 2B, 2A, 6A, 9A, 12A, 12B: I can use
function notation in context.

EQ: How do I evaluate and solve linear functions?

Roles:
Facilitator
Scribe
Resourcer
Includer

Lesson Goals:
● Creative Thinking
● Talk through controversies and conflict
● Recognize and reduce ambiguity
● Encourage thinking based on formulas, vocab,

and prior knowledge

● Help explain ideas to each other
● Own your ideas and work
● Record ideas in your journal
● Answer Questions on Slides
● Follow your team roles

Facilitator

• Make sure that all peers are staying on task.

• Give advice or suggestions to resolve the problem.

• Be sure everyone is able to explain.

Scribe

• Make sure peers organize their results on their own papers.

• Remind peers to use color, arrows, and other math tools to
communicate your mathematics, reasons, and connections.

• Be ready to join the teacher for a huddle.

Resourcer

• Make sure peers are getting the materials needed.

• Make sure that all materials are put away neatly.

• Make sure that peers are logged in to the needed site.

• Help troubleshoot any technology difficulties that may arise.

Includer

• Make sure that all peers are talking about their work.

• Helps keep peers’ voice volume low.

• Encourages everyone to ask questions.

• Communicates conflicts or questions to the teacher.

Poll

What role(s) are you today?

• Facilitator

• Scribe

• Includer

• Resourcer

● Go to your calendar paper.

● Select a skill to work on.

● Work on Deltamath.

When waiting for other groups to be ready…

Part 1: Warming Up with

Function Notation

The parts of the Function Notation f(x) = y

Labelling

Match the term with the part of the diagram.

Drag labels to their correct position on the image

Name of Function

Output

Input

Linear Relation between Celsius and Fahrenheit

Given that water freezes at 0°C, or 32°F; and water boils at 100°C, or 212°F, write the algebraic function rule that relates these quantities, with Celsius as the input and Fahrenheit as the output.

What does the rate of change represent in the context of this problem?

What does the y-intercept represent in the context of this problem?

Multiple Choice

Write the algebraic function rule that relates these quantities, with Celsius as the
input and Fahrenheit as the output.

• F = (C * 9/5) + 32
• F = (C * 5/9) + 32
• F = C + 32
• F = C + 273

Multiple Choice

The rate of change is 1.8. What does that mean in the context of the problem?

• A change of 1.8°F is equivalent to a change of 2°C.
• An increase of 1.8°F corresponds to a decrease of 1°C.
• An increase of 1.8°F corresponds to an increase of 1°C.

Multiple Choice

What does the 32 in your algebraic rule mean in the context of the problem?

• The 32°F is the freezing point of water.

• 32°F is the average temperature of a refrigerator.
• 32°F is the boiling point of water.
• 32°F is the temperature at which water evaporates.

Categorize

Options (4)

F(100) = 212

C(32) = 0

F(0) = 32

F(212) = 100

How can we use function notation to represent the relationships?

Boiling Point

Freezing Point

Random Question of the Day Time

https://wheelofnames.com/4ke-epz We’ll spin the
wheel as a class and spend a minute or so
discussing our answers.

Part 2: Using Function Notation

for a Science Experiment

The Science Experiment

You are doing an experiment in biology class. Your teacher tells
you that the conventional way to measure temperature in the
scientific community is in Celsius. As a result, your lab instructions
are written in Celsius, not Fahrenheit. However, the thermometers
you are using only measure Fahrenheit.

9/5 = 1.8 and 5/9 ~ 0.56

Drag and Drop

Evaluate F(25), and explain what it means in the context of the problem. F(25) =

​

Placeholder

this means that input ​

Placeholder

is the same as output ​

Placeholder

.

Drag these tiles and drop them in the correct blank above

77°F

25°C

-4°C

Multiple Choice

(c) Your lab instructions tell you to take a reading every 10 seconds after the temperature reaches 75°C. You take a reading and the temperature is 170°F. What is the temperature in degrees Celsius?

• 80.05°C

• 75.33°C

• 90.00°C
• 76.67°C

Draw

Draw something related to hot or cold.

Part 3: Practice with

Function Notation in Context

Handout 1.11.B #1

1. Your above-ground pool has sprung a leak, and you do not have a way to fix it. At 12
noon, the water in the pool is 5 feet deep. You are not sure how quickly the pool level is
falling, so you check again after 40 minutes and see that the height of the water level is now
4 feet. You notice that there is a relationship between the time that has passed to the height
of the water level in the pool.
(a) If you assume the height of the water level is decreasing at a constant rate, what will be
the height of the water level at 1 p.m.?
(b) Write a linear function, h, that relates the time past noon, t, in minutes, and the height of
the water level in the pool, h(t), in feet.
(c) Explain the meaning of the rate of change of function h.
(d) Evaluate h(75), and explain its meaning in the context of time passed and height of the
water level.
(e) At what time, t, will h(t) = 0.5? What does your solution mean in the context of the
problem?
(f) When you check the pool at 3 p.m., the height of the water level is approximately 1 foot, 4
inches. What conclusions can you draw?

Handout 1.11.B Answers to #1

t units = minutes
h units = feet

Complete #2-4 on Handout 1.11.B with a Partner

Open Ended

Upload picture(s) of your journal for this lesson. Also write one sentence about what you learned.