Today’s Student Tube lecture is about the Introduction of Sets – Chapter 1 (9 & 10 Mathematics – Sindh Board Education)

A well defined collection of {distinct}objects is called a set.

- The objects are called the elements or members of the set.
- Sets are denoted by capital letters A, B, C …, X, Y, Z.
- The elements of a set are represented by lower case letters a, b, c, … , x, y, z.

**TABULAR FORM **

Listing all the elements of a set, separated by commas and enclosed within braces

or curly brackets{}.

EXAMPLES

In the following examples we write the sets in Tabular Form.

A = {1, 2, 3, 4, 5} is the set of first five Natural Numbers.

B = {2, 4, 6, 8, …, 50} is the set of Even numbers up to 50.

C = {1, 3, 5, 7, 9 …} is the set of positive odd numbers.

**DESCRIPTIVE FORM:**

Stating in words the elements of a set.

EXAMPLES

A = set of first five Natural Numbers.( is the Descriptive Form )

B = set of positive even integers less or equal to fifty.

( is the Descriptive Form )

**SET BUILDER FORM**

Writing in symbolic form the common characteristics shared by all the

elements of the set.

EXAMPLES

A = {x ÎN / x<=5} ( is the Set Builder Form)

B = {x Î E / 0 < x <=50} ( is the Set Builder Form)