3-8 Direct, Inverse, Joint Variation ESSENTIAL QUESTION- How do you write an equation with a direct, inverse or joint variation? How do you solve problems with direct, inverse or joint variation?

Direct Variation y = kxn, n>0 k is the constant of variation As one value incrases, the other value also increases at a constant rate. Examples: The relationship between hours worked and wages (money) earned. As you work more hours, the more wages you earn, increasing at a constant rate. The relationship between braking distance and car speed. As the speed of the car increases, the braking distance also increases at a constant rate

Lesson Overview 3-8A

Inverse Variation (Inversely proportional) As one value increases the other decreases. When you travel to a higher elevation above Earth’s surface, the air temperature decreases.

Lesson Overview 3-8B

Joint Variation – when one quantity varies directly as the product of two or more other quantities. y = kxnzn where x and z cannot = 0 and n > 0

Lesson Overview 3-8C