Sets Definition and Examples

Set

Definition:
Set is a well-defined collection of things or objects

Note:
Sets maybe denoted by capital letters such as A,B,X, Y

An element or member of a set is a thing that belongs to the set and maybe denoted by small letters such as a,b,c……..x,y.

The members of the set are enclose in braces { }, with a comma separating the members.

Example:

The set “A” whose members are ETHEL, CYNTHIA, CHELO, we usually use the symbol.

A = {ETHEL, CYNTHIA, CHELO}

ETHEL Є A
- Read as ETHEL is an element of set A
- Read as ETHEL belongs to set A
- Read as ETHEL is a member of set A

Empty Set and Set

- A set is a collection of things
- An element or member of a set is a thing that belongs to the set.

* There are many words which we use in everyday language that have the same meaning as the word set.

Example:

1. A herb of cattle is a set of cattle
2. A flock of birds is a set of birds
3. A squadron of planes is a set of planes
4. a school of fish is a set of fish
5. A regiment of soldiers is a set of soldiers

* The members of the set are enclosed in braces, { }, with a comma separation the members and to identify sets we often name them by capital letters.

Example:

1. The Set “A” whose members are Ethel, Emerson and Merecel. We usually use the symbol

A = {Ethel, Emerson, Merecel}

2. The Set “B” of days of the week

B = {Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday}

The set C of words to distinguish two faces of a coin

C = {Heads, Tails}

* The set that has no elements is called the empty set, we use the symbol Ǿ to indicate the empty set.

Example of Empty set:

1. the set of whole numbers by 9 and 10.
2. the set of four-sided triangles.
3. the set of astronauts who have landed on the planet Pluto
4. the set of icebergs in the sahara desert
5. the set of people with two heads
6. the set of pink elephants
7. the set of purple cows