Education Technology

Exploring the Exponential Function

Published on 06/09/2008

Activity Overview

Students study the exponential function and differentiate between exponential growth or decay from an equation. They identify the coefficient in an equation that represents the rate of growth/decay. Students also explain the effect of changes in the values of A and B.

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 73 - 83 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to the class.

    Follow the activity procedures:

  • Enter an exponential function ABx in the calculator and set the values of the coefficients to 1
  • Observe the graph
  • Change the value of A and observe the effects on the y-intercept
  • Set A=1 and increase the value of B
  • Observe that B controls the rate at which the function grows
  • Explore how money deposited in a bank earning interest shows exponential growth
  • Examine how the cooling curve, as a cup of hot chocolate cools, represents exponential decay
  • Observe that the exponential equation is asymptotic to zero
  • Study various graphs, determine whether they are growing or decaying, and find the values of A and B
  • 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