This document provides information about sets, including: - The cardinality of a set is the number of elements it contains. - A subset is a set contained within another set. - The universal set contains all objects under consideration. - An ellipsis followed by a last element indicates the set continues in the same manner up to and including that element. - The null set is an empty set and is a subset of any other set.

1. Hello Colegians
RMAN

2. Prayer
Before Study
Lord, true source of light and wisdom, give me
a keen sense of understanding, a retentive
memory and a capacity to grasp things
correctly.
Grant me the grace to be accurate in my
exposition and the skill to express myself with
thoroughness and clarity.
Be with me at the start of my work, guide its
progress and bring it to completion.
Grant this through Christ, our Lord. Amen.
RMAN

3. The cardinality of a set A is
the number of elements
contained in A.
When a set is
contained in another
set B, we say that set A
is a subset of set B.
The universal set is the set
that contains all objects under
consideration
An ellipsis followed by a last
element indicates that the
elements set continue in the
same manner up to and
including the last element.
The null set is an empty set.
The null set is a subset of any
set.
Well-defined set are group of
objects, called elements that
share a common
characteristics.
R e m e m b e r i n g
RMAN

4. Engage yourself
Which of the following shows the union of set A and
set B? How many elements are in the union of A
and B?
Which of the following shows the intersection of
set A and set B? How many elements are there in
the intersection of A and B?
A B
RMAN
Intersection
8
6

5. UNION AND INTERSECTION OF SETS
Lesson 1.2
Let’s dig deeper
The union of two sets is all the elements
from both sets.
Thus, the union of sets A and B, written as
A ∪𝑩, is the set of The
elements that are members of A, or
members of B ,or members of
both A and B.
The intersection of two sets is those
elements that belong to both sets.
Thus, the intersection of sets A and B,
written as A ∩𝑩, is a set of elements that
are members of both A and B.
union intersection
RMAN

6. Note
The complement of A,
written as 𝐴𝑐, is the set
whose elements are in
U but not in A.
RMAN

7. 2020
2019
2018
2017
Think about this
Let U= { 1,2,3,4,5,6,7,8 }
A= { 2 ,4 ,6, 7, 8 }
B= {1, 2, 3, 5, 7}
a. Give A ∪𝐵 and A ∩𝐵
b. Place the elements of these sets in the
proper locations in the given Venn diagram
( some elements are already given)
A
4
B
2 3
U
6
7
8
1
5
A ∪𝐵 = { 1, 2, 3, 4, 5, 6, 7, 8 }
A ∩𝐵 = { 2, 7 }
RMAN

8. Think about this
Given: P= { 1,2,3,4,5,6, }, Q= {2,4,6,8 }, and R= {1,3,5}
Find; a. P ∪ Q
b. P ∪ R
c. P ∩ 𝑅
d. Q ∩ 𝑅
= { 1,2,3,4,5,6,8 }
= { 1,2,3,4,5,6, }
= { 1,3,5 }
= { }
e. Illustrate P ∩ 𝑄 using
Venn diagram P Q
1 2
3
4
5 6
8
RMAN
U

9. THANK YOU
RMAN