Education Technology

Activities

• Subject Area

• Math: Algebra I: Quadratic Functions

9-12

60 Minutes

• Device
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition

TI Connect™

• Accessories

TI Connectivity Cable

• Other Materials
This is Activity 5 from the EXPLORATIONS Book:
Exploring Mathematics with the Transformation Graphing Application.

Investigating the Parabola in Vertex Form (y = ax2 + bx + c)

Activity Overview

In this activity, students investigate the standard form of the quadratic function, y = ax2 + bx + c. They investigate the changes on the graph of a quadratic equation that result from changes in A, B, and C. They also locate the vertex of a parabola when its quadratic equation is expressed in standard form.

Before the Activity

Install the Transformation Graphing application on the students' graphing calculators using one of these two methods:

• TI-Connect™,  a TI Connectivity Cable, and the Unit-to-Unit Link Cable
• TI-Navigator™  "send to class" feature
• See the attached PDF file for detailed instructions for this activity
• Print pages 59 - 68 from the attached PDF file for your class
• During the Activity

Distribute the pages to the class.

• Given the vertex form of a quadratic function, determine the coordinates of the vertex
• Use the standard form of the quadratic equation
• Change the value of C and examine the effect on the graph
• Understand that the value of C gives the y-intercept of a parabola
• Keeping A constant, observe how the graph changes as value of B changes
• Notice the relationship between the x-coordinate and the value of B
• Change the value of A and notice what happens to the x-coordinate and the graph of the parabola
• Write an expression relating the values of A and B to the x-coordinate of the vertex
• Observe that given the vertex, y-intercept and a symmetric point, a parabola can be graphed
• After the Activity

Students will complete the Student Worksheet and answer questions.

Review student results:

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