1. ObjectivesExamples DefinitionActivity Prepared by: Michael Lacsina Val de Guzman

2. At the end of the presentation, students should be able to: Learn what an Inverse Variation equation mean. Learn how to use an Inverse Variation equation. Home

3. Inverse variation is a variation in which the variable y varies inversely as x, if there is a nonzero constant k such that xy = k or, where. Graph of an Inverse Variation Home

4. 1. The number of hours, h, it takes for a block of ice to melt varies inversely as the temperature. If it takes 2 hours for a square inch of ice to melt at 65º, find the constant of proportionality. 2. y is inversely proportional to x. If y = 5 when x = 25, then find the value of x when y = 15. Solution Home

5. 1. Solution: Use the formula y=k/x. Then substitute the values: y=2x=65 After substituting, solve for k. 2=k/65 k=130 Home Back to Examples

6. 2. Solution: Use the formula y=k/x Substitute the known values to find k. 5 = k/25 k = 125 Substitute the values of k and y to find x. 15 = 125/x 15x = 125 Home x = 25/3 Back to Examples

7. Activity 3Activity 2Activity 1 Home Answers

8. Activity 1 If one worker needs 12 hours to complete a job. How many hours do 4 workers to finish a job if they can finish a job at the same rate? Back to Activities

9. Activity 2 Let a rectangle which its area does not change. The length of a rectangle varies inversely as the width. If the length of a rectangle is 20 ft when the width is 8 ft, find the length of the rectangle when the width is 10 ft.? Back to Activities

10. Activity 3 The time to complete a project is inversely proportional to number of people who is doing the project. A certain project can be completed by 5 workers in 24 days. In order to finish the project sooner, the company plans to hire additional workers. How many workers are needed to finish the project in 15 days? Back to Activities

11. Answers Activity 1: 3 hours Activity 2: 16 feet Activity 3: 8 workers Home