# MATHS - SETS Flashcards

Element

The objects in the set are called elements

Set

Is a collection of well defined objects

Cardinal numbers

The number of elements in a set is called the cardinal numbers of the set.

Cardinal numbers symbol

#

Two sets are equal symbol

A=B

Null set

If a set has no elements,then it’s called a null set or empty set

Subset

If all of the elements of a set A are also in a set B,then we say that A is a subset of B.

Subset Symbol

C

Null set

{ }

Union

The union of two sets is the set of elements contained in both sets.The union of the two sets A and B is written as AUB

Intersection

The intersection of two sets is the set of elements that are common to both sets.It is written as A ( upside down “U” ) B

Universal set

Is the set that contains all elements.Every set is a subset of the universal set.

Universal set symbol

Rectangle and “U”

Complement

Is every element in the universal set except for A

Complement

A’