This textbook has been described by the authors as following the “Rule of Four” which discusses each new concept algebraically, graphically, numerically and verbally. It begins in where they see the most logical place – functions. It was written by two community college professors who recognized that their students generally did not have the funds to spend $200, or more, on a precalculus textbook.

They do not mention specific prerequisites but the authors do make the point of wanting their students to learn the concepts and put less reliance on graphing calculators than other similar textbooks do.

Dr. Carl Stitz of Lakeland Community College and Dr. Jeff Zeager of Lorain County Community College have generously made their free precalculus textbook available to all students, not just the ones attending their schools. They also offer something I have not seen before with most free online texts – a FORUM! They actively participate and invite students to share ideas on making the text better and even more importantly ask questions about the material.

They do not offer an answer key or solutions for their free precalculus textbook, which does tend to make this book a challenge for students doing self-study but hopefully the material is presented so well that they will be confident they are doing everything correctly. I guess to, you could drop by their forum and ask them about problems you may be having difficulty with.

## Chapters in *Precalculus* Online Textbook

- Relations and Functions
- Linear and Quadratic Functions
- Polynomial Functions
- Rational Functions
- Further Topics in Functions
- Exponential and Logarithmic Functions
- Hooked on Conics
- Systems of Equations and Matrices
- Sequences and the Binomial Theorem
- Foundations of Trigonometry
- Applications of Trigonometry

Stitz and Zeager have also added a Chapter 0. In it, they cover material for review before beginning the course. The Prerequisites Chapter 0 covers things such as:

- Basic Set Theory and Interval Notation
- Rela Numbe Arithmetic
- Linear Equations and Inequalities
- Absolute Value Equations and Inequalities
- Polynomial Arithmetic
- Factoring
- Quadratic Equations
- Rational Expressions and Equations
- Radicals and Equations
- Complex Numbers

View this Free Online Material at the source:

Free Precalculus Textbook