2-2 Direct Variation
Objective
To write and interpret direct variation equations
Lesson Vocabulary
- direct variation
- constant of variation
The post heights in the Solve It satisfy a relationship called direct variation.
Essential Understanding Some quantities are in a relationship where the ratio of corresponding values is constant.
You can write a formula for a direct variation function as
Problem 1 Identifying Direct Variation From Tables
For each function, determine whether y varies directly with x. If so, what is the constant of variation and the function rule?
-
x y 1 2 3 6 4 8 so y varies directly with x.
The constant of variation is 2.
The function rule is
-
x y 1 4 2 8 3 11 so
y does not vary directly with x.
Think
How do you find the constant of variation?
The constant of variation is the ratio of any y-value to the corresponding x-value.
Table of Contents
- 5-1 Polynomial Functions
- 5-2 Polynomials, Linear Factors, and Zeros
- 5-3 Solving Polynomial Equations
- 5-4 Dividing Polynomials
- 5-5 Theorems About Roots of Polynomial Equations
- 5-6 The Fundamental Theorem of Algebra
- 5-7 The Binomial Theorem
- 5-8 Polynomial Models in the Real World
- 5-9 Transforming Polynomial Functions