Page 9 - Mathematics Class - XI

Unit I Sets and Functions
Sets and Functions

TOPIC - 1: Sets

ACTIVITY 1.1

OBJECTIVE
To find the number of subsets of a given set and verify that if a set has n number of elements, then the total number
of subsets is 2 .
n

MATERIAL REQUIRED
 Paper  Different coloured pencils

PRE-REQUISITE KNOWLEDGE
1. Knowledge of sets and their types 2. Knowledge of subsets

PROCEDURE
1. Take an empty set (say) A which has no element. It is also represented by φ.
0

A 0

Fig. (a)
2. Take a set (say) A which has only one element a in it.
1 1
A = {a }
1
1
•a
1

A
1
Fig. (b)

3. Take a set (say) A which has two elements a and a in it.
2 1 2
A = {a , a }
2 1 2
•a 2
•a 1

A
2
Fig. (c)
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