Course: Algebra III / Intermediate Algebra
Topic: Nonlinear Equations and Applications
Subtopic: Quadratic Equations II - Complete the Square
Overview
This lesson covers the third of four methods for algebraically solving a quadratic equation (the first two being factoring and the root method). The complete the square method has some pretty cool history in that it was used in antiquity to solve quadratic equations purely geometrically even before algebra was invented.
Objectives
By the end of this topic you should know and be prepared to be tested on:
- 11.3.1 Recognize quadratic equations that can be solved by the complete the square method
- 11.3.2 Find the number that must be added to an expression of the form x2+bx to make it a perfect square trinomial so that it can be written as a binomial squared
- 11.3.3 Solve quadratic equations algebraically by the complete the square method
- 11.3.4 Appreciate that the complete the square method has historical significance in mathematics particularly in terms of solving quadratic purely geometrically
Terminology
Define: perfect square trinomial, binomial squared, complete the square method of solving a quadratic equation
Text Notes
Text:
Intro & Inter Algebra for CS 3ed by Blitzer, sect. 11.1 (cont'd)
- This section of the text has too much material. These comments on coverage are a continuation of a previous lesson notes.
- CTS method only works when the coefficient of the x-squared term is 1. Example 7 shows what to do if the coefficient isn't 1.
Supplementary Resources
Explore Interactive CTS and read Geometric Approach to CTS.