Exponential and Logarithmic Models
When you are done with this section, you will be able to do the following

Now that we have learned to solve exponential and logarithmic equation, we are going to look at exponential and logarithmic models.  A mathematical model is an equation used to describe a real world situation.

There are several uses of exponential models:

There are also several uses of logarithmic modes (many of these are well known in name but not as logarithmic models):

When given an exponential and logarithmic model, most problems just require that you plug in a number for one of the variable and solve for another variable.  These problems are often very straight forward.

When finding a model given two data points, you will often need to go through a two-step process.  The first step is the find the growth rate or decay rate (depending on the problem).  The second step is to actually answer the question that is asked.

Problems of this type often need to be practices over and over to get really good at them.  You can find additional examples by logging in as a guest.

One really important thing to remember with all exponential and logarithmic problems is DO NOT ROUND until the very end of the problem. 


A good place to find information about exponential and logarithmic equations is your text book (pages 419-436 and 438-445) in College Algebra 3rd edition by Stewart, Redlin, and Watson).
Additional Exponential and Logarithmic Models On-line Resources:


Exponential and Logarithmic Models Homework:
The Exponential and Logarithimic Models Homework contains 5 problems.
Things to remember:
  • When putting in answers, the only logarithms that you can use are log (log base 10) and ln (log base e).  If you have a logarithm with any other base, you will need to use the change of base formula.
  • If you put in your answers in decimal form, you must have at least 4 digits to the right of the decimal.
  • In solving this type of equation, do not round any number until the very end of the problem.
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Homework examples:
Keep in mind that it is recommended that you also complete all the problems in the set called "also recommended" with the same number as the Exponential and Logarithmic Models Homework.  There are many different ways to ask the same questions.  This will allow you to see additional problems that are related to this topic.

© 2005 Elizabeth E. K. Jones and the ASU Department of Mathematics and Statistics - All rights reserved.