Graphing Linear Functions

and Slope Intercept Form

Warm Up

Fill in the slope of the following points.

(3,5) , (9,7)

(2,4) , (5,6)

(4,9) , (9,9)

(3,7) (4,6)

Objective

The student will be able to to identify key features in slope intercept form and graph linear functions without a function table.

Exploration

Linear Functions Exploration Worksheet.

Try with a Partner

Mr. Holocker is saving up for a tropical vacation to the Bahamas. He puts away $100 each month and currently has $300 in his savings. He needs to save up $1,500 to go on the trip.

Write a function as the number of months m relates to the amount saved.

Identify the slope of this function and state what it means in the context of the problem.

Identify the y-intercept of this function and state what it means in the context of the problem.

Slope Intercept Form

Slope intercept form is one of the most common ways linear equations and functions are written out.

What does this mean and where have we seen this before?

Try with a Partner

Mr. Holocker has a $25 Dunkin Donuts gift card. Each morning he gets a coffee and two donuts for $3.00.

Write a function that relates the days gone to Dunkin Donuts d and the amount of money left on the card.

What is the slope of the function and what does it mean in the context of the problem?

What is the y-intercept and what does it mean in the context of the problem?

On Your Own:

Calvin and Hobbs sell t-shirts to save up for the new Xbox One. Together they have $50 saved to buy the Xbox. They sell their t-shirts for $3.00 a piece.

Write a function that relates the number of t-shirts sold t to the amount of money made.

What is the slope of the function, and what does it mean in context of the problem?

What is the y-intercept, and what does it mean in context to the problem?

Try with a Partner

Graph the following function without using a function table:

Graphing Linear Functions Without a Function Table

Steps:

Start at the y-intercept

Follow the slope.

In this case down 3 (y)

To the left 4 (x)

With a Partner…

Graph the following equation representing profits of a lemonade stand:

Why does it have a negative y-intercept?

On your Own…

Graph the following function representing minutes on a pre-paid cell phone:

What does the slope mean in the context of the problem?

Exit Ticket and Homework

Homework:

Worksheet

Exit Ticket:

Identify the slope and y-intercept: