Education Technology

Precalculus: Change Of Base
by Texas Instruments

Published on January 24, 2012

Overview

Discover the change of base rule for logarithms by examining the ratio of two logarithmic functions with different bases.

Key Steps

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    In Problem 1, students use the program DIFFBASE to compare the graphs of two logarithmic functions with different bases.

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    In Problem 2, students investigate the value of c, a constant factor, as the values of the bases of the logarithmic functions change.

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    Students can then use the values of the bases and c stored in a table, to guess a formula for calculating c.