# Functions and Graphs

By M Bourne

In the real world, it's very common that one quantity **depends** on another quantity.

For example, if you work in a fast food outlet, your pay packet depends on the number of hours you work. Or, the amount of concrete you need to order when constructing a building will depend on the height of the building.

This chapter is about **functions** (this is how we express relationships between quantities) and their **graphs**.

The graph of a function is really useful if we are trying to **model** a real-world problem. ("Modeling" is the process of finding the relationships between quantities.)

Sometimes we may not know an expression for a function but we do know some values (maybe from an experiment). The graph can give us a good idea of what function may be applied to the situation to solve the problem.

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Chapter Contents

- Functions and Graphs
- 1. Introduction to Functions
- 2. Functions from Verbal Statements
- 3. Rectangular Coordinates
- 4. The Graph of a Function
- 4a. Domain and Range of a Function
- 4b. Comparison calculator BMI - BAI
- 5. Graphing Using a Computer Algebra System
- 5a. Online graphing calculator (1): Plot your own graph (JSXGraph)
- 5b. Online graphing calculator (2): Plot your own graph (SVG)
- 6. Graphs of Functions Defined by Tables of Data
- 7. Continuous and Discontinuous Functions
- 8. Split Functions
- 9. Even and Odd Functions