1.1 Introduction

NCERT Class 11 Mathematics for blind and visually impaired students made screen readable by Professor T K bansal..

The concept of set serves as a fundamental part of the present day mathematics. Today this concept is being used in almost every branch of mathematics. Sets are used to define the concepts of relations and functions. The study of geometry, sequences, probability, etc. requires the knowledge of sets.

The theory of sets was developed by German mathematician George Cantor (1,845-1,918). He first encountered sets while working on "problems on trigonometric series". In this Chapter, we'll discuss some basic definitions and operations involving sets.