Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Linear Functions

9-12

50 Minutes

• ##### Device
• TI-83 Plus Family

TI Connect™

• ##### Accessories

TI Connectivity Cable

• ##### Other Materials
This is Activity 1 from the EXPLORATIONS Book:
A Hands-On Look at Algebra Functions: Activities for Transformation Graphing .

## How Many Drivers? Investigating the Slope-Intercept Form of a Line

#### Activity Overview

In this activity, students will be introduced to the slope-intercept form of a linear equation. They will recognize the effects of changes in the slope and y-intercept on the graph of a line. Students will use the Transformation Graphing application to find an approximate linear model of the actual data. They will use the guess-and-check strategy, manipulate the values of the slope and y-intercept to determine the line of best fit.

#### Before the Activity

• Set up the Transformation Graphing on the calculator using the TI Connect™ software
• See the attached PDF files for detailed instructions for this activity
• Print pages 1 - 8 from the attached activity PDF file for the class
• #### During the Activity

Distribute the printed pages to the class.

• Plot graphs for the linear equation y = mx + b on the calculator and observe how the graph changes with variations in m and b values
• Write an hypothesis on the effect of m and b on the graph of a line
• Start the Transformation Graphing Application and graph the equation y = Ax + B
• Set the starting values for the coefficients and the increment and observe the change in the coefficients.
• Compare the results with the hypothesis
• Using the hypothesis, identify graphs of equations and answer questions; verify using the calculator

• Prepare a scatter plot showing the relationship between the population and number of licensed drivers; identify the independent variable and the pattern in the relationship
• Estimate the values of the slope and y-intercept for the linear model
• Use the estimates to graph lines; adjust values of the coefficients to obtain a reasonable model that fits the data
• #### After the Activity

Students' answer questions on the homework page.

Review student results:

• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary