Page 8 - Mathematics_Form_3

Relations

Chapter One

Relations
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Introduction

In daily life, people and things relate in some ways. For example, in families,
there is a unique way on how family members relate. Children relate to their
parents by birth. You may relate to a certain school by being a student at
that school. In this chapter, you will learn about the relations between two
sets. Also, you will learn how to draw graphs of relations, determine the
domain and range of relations, find the inverse of relations, draw graphs
of inverse relations, and state domain and range of inverse relations. The
competencies developed will help you to analyse issues in real life situations
such as relationships of family members, fares against travelling distances,
changes of temperature with time, students and their performance grades,
and many other applications.

Think
Comparisons in mathematics, computer programming, family
structures without the concept of relations.

Meaning of a relation
A relation is a set of ordered pairs. It Furthermore, if a is an element from set
associates an element of one set A with A and b is an element from set B, then
one or more elements of another set B. the relation R is written as
Usually, a relation is denoted by the letter Mathematics for Secondary Schools
R = {(a, b ): a ∈ A, b ∈ B} .
R. In set notation, the relation R between
two sets A and B can be written as The notation, a ∈ A, b ∈ B means that a

R = {(a, b ) : a is an element of set A and is a member of set A and b is a member of
b is an element of set B} . set B. Additionally, the notation a 
b
The relation R, is read as R is a set of means ʻa is mapped onto bʼ. For instance,
ordered pair (a, b) such that a is an ʻx is mapped onto 3 times xʼ is written
element of set A and b is an element as x ! 3x.
of set B.

Student\s Book Form Three 1

18/09/2025 09:58:33
MATHEMATIC F3 SB.indd 1
MATHEMATIC F3 SB.indd 1 18/09/2025 09:58:33