8.7 Solving Quadratic Inequalities

1. 8.7 Solving Quadratic Inequalities Algebra 2 Mrs. Spitz Spring 2007

2. Announcements • No School on Friday due to Parent/Teacher conferences. This an opportunity for your parents to get a get out of 1 homework assignment free for you. • I will check 8.1, 8.3, 8.4 and 8.6 assignments. These are new assignments for the 4th quarter. • Test on Thursday. You must be excused to take the make-up exam. I would recommend you take this before you go on Spring Break!!! You will not be taking the same exam when you return, and I guarantee it will be harder.

3. Reminders: • Attendance—especially seniors. You fail at 11 absences. This is the Taos Municipal School District policy. You must have a 90% attendance rate in order to get credit for a class. (Especially SENIORS and especially if you want to graduate!) • Wednesday 8.7/Chapter 8 Review • Thursday Chapter 8 Exam/Binder due with all notes

4. Objectives • Solve quadratic inequalities in one variable. Assignment • pg. 386 #4-45 all

5. Ex. 1: Solve (x – 7)(x + 2) > 0 Another way that you can solve quadratic inequalities is by using three test points. First, solve the equation (x – 7)((x + 2) = 0 x – 7 = 0 x + 2 = 0 x = 7 x = -2

6. Ex. 1: Solve (x – 7)((x + 2) > 0 The points 7 and -2 separate the x-axis into three parts x < -2, -2 < x < 7, or x > 7

7. Ex. 1: Solve (x – 7)((x + 2) > 0 The points 7 and -2 separate the x-axis into three parts x < -2, -2 < x < 7, or x > 7

8. Ex. 2: State the signs of the factors of each quadratic inequality (x – 9)(x + 1) < 0 x – 9 = 0 x + 1 = 0 x = 9 x = -1 So one factors sign will be positive, the other negative. one factor > and one factor is <

9. Ex. 3: Solve each inequality (a – 10)(a – 3) ≤ 0 a – 10 ≤ 0 a – 3 ≤ 0 a ≤ 10 a ≤ 3 a ≤ 10 and a ≥ 3 or a ≥ 10 and a ≤ 3 OR 3 ≤ a ≤ 10 or {a|3 ≤ a ≤ 10}