# User:Lizynavin/My sandbox/Maths

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< User:Lizynavin | My sandbox

## Contents

**Relations and Functions**

**Relations and Functions****Relation**

#### A **relation**is defined to be any set of ordered pairs.

**relation**

### Representation of Relations

- Set Notation
- Mapping Diagram
- Tables
- Graph

**Functions **

#### A relation in which corresponding to every input there is only one output is called a **function**.

**function**

**Function Notation**

The symbol *f(x)* is read as "the value of *f *at*x" * or simply " *f of x " . *It doesnot mean f times x. *f(x) *is called the <u>**function notation.**

**Evaluating a Function**

Consider the function f(x) .To evaluate f(a)

- Replace all x`s with
*a*in the definition of f(x) - Simplify the expression

**Example :**__ Let f(x) = 2x -3 .Find f(-1)
__

* Solution :*f(-1) = 2(-1) -3

= -2-3

= -5