Common and Natural Logarithms

Contributed by:
Sharp Tutor
OBJECTIVES:
1. Evaluate common logarithms using a calculator.
2. Use common logarithms in applications.
3. Evaluate natural logarithms using a calculator.
4. Use natural logarithms in applications.
1. Copyright © 2010 Pearson Education, Inc. All rights reserved
Sec 11.5 - 1
2. Chapter 11
Inverse, Exponential
and
Logarithmic Functions
Copyright © 2010 Pearson Education, Inc. All rights reserved
Sec 11.5 - 2
3. 11.5
Common and Natural
Logarithms
Copyright © 2010 Pearson Education, Inc. All rights reserved
Sec 11.5 - 3
4. 11.5 Common and Natural Logarithms
Objectives
1. Evaluate common logarithms using a
calculator.
2. Use common logarithms in applications.
3. Evaluate natural logarithms using a
calculator.
4. Use natural logarithms in applications.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 4
5. 11.5 Common and Natural Logarithms
Common Logarithms
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 5
6. 11.5 Common and Natural Logarithms
Common Logarithms
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 6
7. 11.5 Common and Natural Logarithms
Evaluating Common Logarithms
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 7
8. 11.5 Common and Natural Logarithms
Common Logarithms in Applications
The loudness of sound in decibels is given by the formula
 I 
y 10log  
 I0 
Where I0 is the weakest sound detected by the observer and I is
the intensity of the given sound.
That is, find the value of I0 is 51,000 times I.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 8
9. 11.5 Common and Natural Logarithms
Common Logarithms in Applications
 I 
y 10log  
 I0 
 51,000 
y 10log  
 I0 
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 9
10. 11.5 Common and Natural Logarithms
Natural Logarithms and Evaluation
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 10
11. 11.5 Common and Natural Logarithms
Natural Logarithms and Evaluation
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 11
12. 11.5 Common and Natural Logarithms
Applications of Natural Logarithms
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 11.5 - 12