### Introduction

This Section provides a catalogue of some common functions often used in Science and Engineering. These include polynomials, rational functions, the modulus function and the unit step function. Important properties and definitions are stated. This Section can be used as a reference when the need arises. There are, of course, other types of function which arise in engineering applications, such as trigonometric, exponential and logarithm functions. These others are dealt with in
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#### Prerequisites

- understand what is meant by a function and use functional notation
- be able to plot graphs of functions

#### Learning Outcomes

- state what is meant by a polynomial function, and a rational function
- use and graph the modulus function
- use and graph the unit step function

#### Contents

1 Polynomial functions2 Rational functions

3 The modulus function

4 The unit step function