Algebra II Essentials For Dummies

Chapter 3

Making Quick Work of Quadratic Equations

IN THIS CHAPTER

Solving quadratic equations by factoring or taking roots

Using the quadratic formula

Coming to grips with quadratic inequalities

Aquadratic equation contains a variable term with an exponent of 2, and no term with a higher power. The standard form is . Quadratic equations potentially have two real solutions. You may not find two, but you start out assuming that you’ll find two and then proceed to prove or disprove your assumption. Quadratic equations also serve as good models for practical applications.

In this chapter, you discover many ways to approach both simple and advanced quadratic equations. You can solve some quadratic equations in only one way, and you can solve others by readers’ choice (factoring, quadratic formula, or by-guess-or-by-golly) — whatever your preference. It’s nice to be able to choose. But if you have a choice, I hope you choose the quickest and easiest ways possible, so I cover these first in this chapter (except for by-guess-or-by-golly).

Using the Square Root Rule When Possible

Some quadratic ...