Lesson 5 Summary

 

In this lesson you explored the laws of logarithms. You used numeric values to determine what the laws should be and, then, looked at how the laws could be derived. You studied the following laws:

• product law of logarithms:
  
  
   
  logb (M × N) = logb M + logb N
• quotient law of logarithms:
  
  
   
  
• power law of logarithms:
  
  
   
  logb (Mn) = nlogb M

The laws of logarithms can be used to evaluate logarithmic expressions as well as expand or simplify logarithmic expressions.

 

You also saw how logarithmic scales are used. You solved problems involving the decibel scale and the pH scale.

 

Using the laws of logarithms to expand or simplify logarithmic expressions will be helpful in the next lesson. In Lesson 6 you will solve logarithmic equations.