# Ch 19: Exponential Functions & Logarithms in Precalculus

### About This Chapter

## Exponential Functions in Precalculus - Chapter Summary and Learning Objectives

These short videos explain what is meant when we say that a number or value increases exponentially. As you work through the lessons, you will find out how this works and be able to apply these concepts to everyday realities. The videos will help you understand things like:

- How to identify and explain what an exponential function is
- Calculating, comparing and contrasting exponential growth and decay
- What logarithms are and how to work with them
- The meaning and application of natural base
- Graphing logarithms and logarithmic functions
- How to transform an exponential function

## Course Topics

Video | Objective |
---|---|

What Is an Exponential Function? | Identify exponential functions |

Exponential Growth vs. Decay | Describe and compare exponential growth and decay |

Transformation of Exponential Functions: Examples, Lesson & Quiz | Explore exponential horizontal and vertical transformations |

Using the Natural Base e: Definition, Lesson & Quiz | Explain and graph natural base functions |

What is a Logarithm? | Discover logarithms and their applications |

How to Evaluate Logarithms | Learn how to evaluate logarithms |

Writing the Inverse of Logarithmic Functions: Lesson & Quiz | Transpose logarithmic equations |

Exponentials, Logarithms & the Natural Log | Review basic properties |

Basic Graphs & Shifted Graphs of Logarithmic Functions: Definition & Examples | Graph a logarithmic function |

Logarithmic Properties | Describe and use logarithmic properties |

Practice Problems for Logarithmic Properties | Practice working with logarithmic properties |

How to Solve Logarithmic Equations | Solve logarithmic equations with exponentials |

Using the Change-of-Base Formula for Logarithms: Definition & Example | Explain and use the change-of-base formula |

How to Solve Exponential Equations | Work with exponential equations with logarithms |

Behavior of Exponential and Logarithmic Functions | Examine functions with different bases |

### 1. What Is an Exponential Function?

Brand new technologies don't always catch on right away because they can be expensive and don't always work as well as they should. But once the price comes down, and they start to work better, it doesn't take very long before it seems like everyone has one. Learn about the numbers behind this, exponential functions!

### 2. Exponential Growth vs. Decay

How is it that it only takes four years for our computer to go from top-of-the-line to almost worthless? Well, it has something to do with what's called exponential decay, which we'll learn about here!

### 3. Transformation of Exponential Functions: Examples & Summary

All exponential functions follow a basic graph. But when you make changes to the function, you will see the graph shift and make changes. Watch this video lesson to learn how to easily identify these changes or transformations.

### 4. Using the Natural Base e: Definition & Overview

In this video lesson, you will learn what kind of number 'e' is. Also learn the formal name for this unique number. See what kind of graph the natural base 'e' graphs into, as well as the uses of these types of functions.

### 5. What is a Logarithm?

Logarithms can help you solve exponential functions. In this lesson, you will learn about how to work with and recognize logarithms, and how to use logarithm notation with an example problem about earthquakes!

### 6. How to Evaluate Logarithms

Using this lesson, you can get practice evaluating logarithms, as well as learn some of the shortcuts behind writing and estimating them. You can also learn how to use your calculator to evaluate logarithms, and learn about a concept called the change of base theory.

### 7. Writing the Inverse of Logarithmic Functions

Watch this video lesson to learn how inverses are related to the original function. Also learn a method to find the inverse of logarithmic functions that you can easily use.

### 8. Exponentials, Logarithms & the Natural Log

Use the properties of exponentials and logarithms to learn how carbon dating works. This lesson covers properties of a natural log and rules of logarithms.

### 9. Basic Graphs & Shifted Graphs of Logarithmic Functions: Definition & Examples

Watch this video lesson and you will see what the basic graph of the logarithmic function looks like. You will also be able to identify the kind of shifts that will occur by just looking at a logarithmic function when you finish the video.

### 10. Logarithmic Properties

Along with the change of base property, there are three other logarithmic properties that allow you to manipulate expressions to your advantage. Learn about the product rule, quotient rule and power rule here.

### 11. Practice Problems for Logarithmic Properties

As you get further and further into mathematics, logarithms will appear more and more. It's the point of this lesson to get you used to dealing with them and able to know what to do when you see a whole line of paper full of them!

### 12. How to Solve Logarithmic Equations

If you're ever picking out a telescope to see your favorite planet, make sure you do the math first! Learn how to solve the logarithmic equation that will get you the size telescope you want.

### 13. Using the Change-of-Base Formula for Logarithms: Definition & Example

Logarithms have many uses in the real world. But what happens when the calculation uses a base other than the standard base 10? Watch this video to find out how to handle this situation and the formula to use.

### 14. How to Solve Exponential Equations

Read this lesson to learn the steps you need to take to solve exponential equations. You'll see that it's not too difficult; you just need to make use of one other mathematical operation in order to solve your problems.

### 15. Behavior of Exponential and Logarithmic Functions

After watching this video lesson, you will be able to recognize exponential and logarithmic functions by looking at the end behavior of the graphs. You will also learn how the graphs change.

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### Other Chapters

Other chapters within the Honors Precalculus Textbook course

- Working with Linear Equations
- Working With Inequalities
- Absolute Value Equations
- Working with Complex Numbers
- Systems of Linear Equations
- Mathematical Modeling for Precalculus
- Introduction to Quadratics
- Working with Quadratic Functions
- Geometry Basics for Precalculus
- Types of Functions in Precalculus
- Understanding Function Operations
- Graphing Functions in Precalculus
- Graph Symmetry
- Rate of Change
- Polynomial Function Basics in Precalculus
- Higher-Degree Polynomial Functions
- Rational Functions & Difference Quotients
- Rational Expressions & Function Graphs in Precalculus
- Using Trigonometric Functions
- Trigonometric Graphs
- Solving Trigonometric Equations
- Trigonometric Identities
- Trigonometric Applications
- Graphing Piecewise Functions in Precalculus
- Vectors in Precalculus
- Matrices and Determinants in Algebra
- Understanding Arithmetic Sequences & Series
- Understanding Geometric Sequences & Series
- Analytic Geometry and Conic Sections
- Polar Coordinates and Parameterizations
- Working with Sequences & Series
- Sets & Probability
- Continuity
- Limits in Precalculus