# Activities

• • • ##### Subject Area

• Math: Algebra I: Functions and Relations
• Math: Algebra II: Polynomials

• ##### Author 9-12

30 Minutes

• ##### Device
• TI-73 Explorer™
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition
• TI-Navigator™
• ##### Report an Issue

Student Generated Cubic Functions

#### Activity Overview

While using the TI-Navigator™, students will attempt to create a cubic regression equation given three, two, and one x-intercept.

#### Before the Activity

If you are using the TI-Navigator System with the TI-73 you will need the attached .pdf file.
The teacher is to be in the graph + equation mode in the TI-Navigator's Activity Center.

Select a point to be plotted that exists on the x-axis, and plot it.

#### During the Activity

Ask the students to try to come up with a cubic equation that will intersect the specified point.

Once they have mastered this exercise, plot just 2 x-intercepts, and ask the students to find an equation that passes through both.

Finally, plot three points and ask them to come up with an equation that intersects all three.

#### After the Activity

At the conclusion of the activity, discuss how a cubic equation can be created by multiplying y = (x - z1)(x - z2)(x - z3); where z represents a zero.