## Monday, December 5, 2011

### Open Precalculus Textbook

I am almost through my first semester using the following open source Precalculus textbook:

It covered all of the topics that I needed without supplementation and the students liked its readability... and of course the cost. I especially liked the continuing coverage of inequalities and heavy use of sign charts throughout. The pdf is well produced and easy to navigate using the linked TOC. Buying a printed copy was easy and the quality was good -- the Trigonometry portion is printed separately.

I will definitely use it again and I recommend it to anyone teaching this course.

---

## Saturday, December 3, 2011

### Sample Algebra Test Questions

Sample exam questions for Elementary Algebra chapters 1 - 7. These are pdf files stored in google docs.

Ch. 1 - Real Numbers and Their Operations
Ch. 2 - Linear Equations and Inequalities
Ch. 3 - Graphing Lines
Ch. 4 - Solving Linear Systems
Ch. 5 - Polynomials and Their Operations
Ch. 6 - Factoring and Solving by Factoring
Ch. 7 - Rational Expressions and Equations

You can use these to study for the final exam.

---

## Friday, December 2, 2011

### Solving Rational Equations in Beginning Algebra

A thorough explanation for solving rational equations can be read for free in the Elementary Algebra textbook that is available on the Flat World Knowledge website:

Also, you can click on the following rational equation to watch a video solution.

The basic steps for solving these equations are as follows:

Step 1: Factor all denominators and determine the LCD.
Step 2: Identify the restrictions.
Step 3: Multiply both sides of the equation by the LCD. Distribute carefully and then simplify.
Step 4: Solve the resulting equation.
Step 5: Check for extraneous solutions.

The complete solution is presented below:

Basically, we multiply both sides of the equation by the LCD as a means to clear the fractions.  This introduces the possibility for extraneous solutions and so we must check our answers.  Look for more Chapter 7 videos here.

## Thursday, December 1, 2011

### Elementary Algebra (Ch. 9) Solving Quadratic Equations and Graphing Parabolas

Elementary Algebra is an open textbook that is available to read for free on the flatworld knowledge website. Chapter 9 gives an introduction to solving general quadratic equations and graphing quadratic functions. In addition, complex numbers and complex solutions are covered.

9.1 Extracting Square Roots
9.2 Completing the Square