Chapter 1
Linear Equations and Graphing
Course: Gre
Subject: Gre Quantitative Reasoning
Chapter: Quadratic Equations And Polynomials
Introduction: The Soda Machine Revisited
Returning to the soda machine analogy, not everything can be inserted. Pennies do not work. Credit cards from other countries may be rejected. The machine accepts only certain forms of payment—these are the domain. Similarly, the machine produces only certain drinks—no cheeseburgers, no pizza—these are the range.
In mathematics, the domain of a function is the set of all possible input values. The range is the set of all possible output values.
Defining Domain and Range
| Term | Definition | In Soda Machine Terms | | Domain | All possible input values | Dimes, quarters, dollar bills, accepted cards | | Range | All possible output values | Regular soda, diet soda, lemon-lime |
Example: Table of Values
| x | f(x) | | 1 | 3 | | 2 | 6 | | 3 | 9 | | 4 | 12 |