Lesson 5: Laws of Logarithms

Focus

In this module you have learned about logarithms and how they relate to an exponential expression. In the past, you have worked with expressions that have more than one power. You have used the laws of powers to simplify multiple powers in an expression. Do you think there are laws of logarithms that can be used to simplify an expression with multiple logarithms? How would these be related to the laws of powers?

Logarithmic scales are helpful when working with values that are very large or very small. In the case of the pH scale, the values are very small. How can taking the logarithm of a value help determine the pH of a substance?

Lesson Outcomes

At the end of this lesson you will be able to

• demonstrate an understanding of the product, quotient, and power laws of logarithms
• apply the laws of logarithms to determine equivalent logarithmic expressions

Lesson Question

You will investigate the following question:

• How can the product, quotient, and power laws of logarithms be applied?

Assessment

Your assessment may be based on a combination of the following tasks:

• completion of the Lesson 5 Assignment (Download the Lesson 5 Assignment and save it in your course folder now.)
• course folder submissions from Try This and Share activities
• additions to Formula Sheet
• work under Project Connection