Symbols used — lesson. Mathematics State Board, Class 9.

PUMPA - SMART LEARNING

எங்கள் ஆசிரியர்களுடன் 1-ஆன்-1 ஆலோசனை நேரத்தைப் பெறுங்கள். டாப்பர் ஆவதற்கு நாங்கள் பயிற்சி அளிப்போம்

Book Free Demo

Finite set: A set that has a finite number of elements is called finite set.

Example:

The set of positive integers less than $50$ .
The set of prime factors of $275$ .
The set of vowels in alphabets.
The set of keys on the laptop.

Infinite set: A set that has an infinite number of elements is called an infinite set.

Example:

The set of rational numbers.
The set of powers of $2$ .
The set of multiples of $6$ .
The collection of all even integers.

Set notation: A set is denoted by capital letters English alphabets

$A, B, C, D,...$

Elements: Elements of the sets are denoted by small letters English alphabets

$a, b, c,...$

Also, elements of the set should be written inside the curly brackets

$\{\}$ .

Important!

Suppose the element

$x$ lies in the set

$A$ , then we can say that as

$x$ belongs to the set

$A$ . That is,

$x$

$\in$

$A$ .

Suppose the element

$x$ doesn't lie in the set

$A$ , then we can say that

$x$ does not belong to the set

$A$ . That is,

$x$

$\notin$

$A$ .

Example:

Consider the set

$A = \{2, 4, 6, 8, 10\}$ .

Here

$2$ is an element of

$A$ . That is

$2 \in A$ .

$4$ is an element of

$A$ . That is

$4 \in A$ .

$6$ is an element of

$A$ . That is

$6 \in A$ .

$8$ is an element of

$A$ . That is

$8 \in A$ .

$10$ is an element of

$A$ . That is

$10 \in A$ .

But the element

$5$ doesn't belong to

$A$ . That is

$5 \notin A$ .

Previous theory

Exit to the topic

Next theory

Send feedback

Did you find an error?

Send it to us!

2. Symbols used

Theory: