Review of Lesson 16
Transcript of Review of Lesson 16
Alg2 2.7 Notes.notebook September 26, 2012
27 Solving Quadratic Inequalities
Review of Lesson 16:1. Find the zeros of 2. Find the roots ofSkills Needed For Today:1. Graph the inequality y < 2x + 12. Solve x2 16x + 63 = 0 by factoring3. Solve 3x2 + 8x = 3 by factoring
Review of Lesson 16:1. Find the zeros of
2. Find the roots of
Alg2 2.7 Notes.notebook September 26, 2012
27 Solving Quadratic Inequalities
Solve quadratic inequalities by using tables and graphs.
Solve quadratic inequalities by using algebra.
Profit analysis: Profit can sometimes be modeled by a quadratic function of an item's selling price. We can determine the range of selling prices that result in a profit.
Alg2 2.7 Notes.notebook September 26, 2012
I. Graphing Quadratic Inequalities1) Graph
*check with a test point
2) Graph
Alg2 2.7 Notes.notebook September 26, 2012
II. Solving Quadratic Inequalities by Graphing
3) Solve
III. Solving Quadratic Inequalities by a Table
Alg2 2.7 Notes.notebook September 26, 2012
IV. Solving Quadratic Inequalitiesby Using Algebra
Ex. 3 continued: x2 + 8x + 20 ≥ 5
*Find the Critical Points!
4) Solve the inequality x2 – 10x + 18 ≤ –3by using algebra.
Alg2 2.7 Notes.notebook September 26, 2012
V. ApplicationThe monthly profit P of a small business that sells bicycle helmets can be modeled by the function P(x) = –8x2 + 600x – 4200, where x is the average selling price of a helmet. What range of selling prices will generate a monthly profit of at least $6000?
Use the Quadratic Formula.
x ≈ 26.04 or x ≈ 48.96
For a profit of $6000, the average price of a helmet needs to be between $26.04 and $48.96, inclusive.
Will there always be one region that works and one that doesn't around a critical point?
Alg2 2.7 Notes.notebook September 26, 2012
27 p.114 #2 11, 15 57 (x3), 59 64, 66 68Factoring Worksheet 105 #1 12Factoring Worksheet 106 #1 9
*Group Quiz Friday on Ch. 2.1 to 2.7 (See p.109 for ideas)