Using a TI-84 Plus as an investigative tool

Topic of Lesson/Activity: How do changing the parameters of m and b effect the graph of y = mx + b?

 

Grade/Subject: 9^th Grade Algebra 1

 

Introduction: Students will be investigating how the change in m (slope) and the change in b(y-intercept) will effect the linear graph of y = mx + b.  Students will be using a program called Transformations on their TI-84 Plus calculators to perform this investigation.

 

Materials: TI-84 Plus, paper and writing utensil.  This project would be greatly enhanced with a video projection system where the teacher could model the use of the calculator for the class.

 

Procedure:

 

Step 1

 

Follow the procedures found at TI’s website on how to use Transformations: http://education.ti.com/downloads/demo/TransGraphx.pdf . 

 

 

Step 2

 

Allow students some time to investigate what occurs to the line with the change in A (which is really m) and B.

 

Step 3

 

Have the students answer the following questions individually:

 

1. What do you notice happens to the graph of the line when A(which is really m) is increased?
2. What do you notice happens to the graph of the line when A(which is really m) is decreased?
3. What do you notice happens to the graph of the line when B is increased?
4. What do you notice happens to the graph of the line when B is decreased?

 

Step 4

The students will now compare their answers with a fellow student.

 

Step 5

The teacher will facilitate a discussion that helps all students understand the correct answers to the question.

 

Goal: Students will become comfortable investigating any graph using the TI-84 Plus.