1. Review: 9.4d Mini-Quiz 1. The time t for a pendulum of length L to go through one cycle is given by the formula: How long is the pendulum of a mantel clock with a period of 4 seconds? 2. A 12 foot skateboarding ramp has a height of 4 feet (see the figure). Find the base length of the ramp.

2. Class Greeting

3. Chapter 9 Radical Expressions and Equations Lesson 9-4b Radical Equations and Applications

4. Objective: The students will solve word problems involving radical equations. (continued)

5. Applications of Radicals

6. The demand equation for a video game is: where x is the number of units demanded per day and p is the price per game. Find the demand when the price is set at $20. Answer: The demand for the video game is 401 units when the price is set at $20.

7. The vibration of a string on a guitar depends on the length of the string. The table shows the velocities v (in meters per second) at different lengths l (in meters). Graph the data and approximate the length of the string when the velocity is 200 meters per second. Verify your approximation by solving the equation.

8. Answer: The length of the string when the velocity is 200 meters per second is about 0.42 meters.

9. Lesson Summary: Objective: The students will solve word problems involving radical equations. (continued)

10. Preview of the next Lesson: Objective: The students will practice for the Midterm Exam.

11. Homework 539/87 and 89

12. Stand Up Please