Education Technology

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.