1. Intersection and Union of Sets

2. Objectives
Understand the difference between intersection and union of sets.
Identify the intersection and the union of sets.

3. Intersection and Union of Sets
A set is a group of distinct objects or data of some kind.
A set can contain any kind of data from names to numbers to places. In math, sets normally contain numbers in the form of data.

4. Intersection and Union of Sets
The intersection of two sets are the elements that occur in both sets.
The intersection of sets is denoted with the ∩. Mathematically, it will appear as A ∩ B.
If we are to think in terms of “English” we would say “the intersection of set A and B.
*We can think of the ∩ as “and”.

5. Intersection and Union of Sets
The union of two sets are the elements that occur in one set or in the other sets.
The union of sets is denoted with the ∪. Mathematically, it will appear as A ∪ B.
If we are to think in terms of “English” we would say “the union of set A or B.
*We can think of the ∪ as “or”.

6. Intersection and Union of Sets
To visualize the intersection and union of two or more sets we can use a venn diagram.
For instance, suppose
Set x = {6, 5, 14, 7, 12} Set y = {5, 17, 6, 9, 8, 11}
X ∩ Y = {5,6} 17 11 8 9 14 12 7 5 6
X ∪ Y = {5,6,7,8,9,11,12,14,17}

7. Henry Ana Example - Intersection and Union of Sets Green Blue Black
Given the venn diagram identify the colors that Ana likes to use in her art and the colors that Henry likes to use.
Tan
Brown
Green
White
Black
Red
Blue
Henry
Ana
Ana = {Black, Blue, Red, White}
Henry = {Blue, Brown, Green, Red, Tan}

8. Henry Ana Example - Intersection and Union of Sets Green Blue Black
Given the venn diagram identify the intersection and the union of Ana’s and Henry’s color palette.
Tan
Brown
Green
White
Black
Red
Blue
Henry
Ana
Henry ∩ Ana = {Blue, Red}
Henry ∪ Ana = {Black, Blue, Brown, Green, Red, Tan, White}

9. Example - Intersection and Union of Sets
The given venn diagram shows the sports that three students play throughout the year Ed
Mia
Mike
Hockey
Golf
Tennis
Cross Fit
Badminton
Basketball
Softball
Wrestling
Baseball
Boxing

10. Basketball!!!  Example - Intersection and Union of Sets
Answer the following questions.
1) Identify the set of sports that Mia and Ed enjoy.
{Basketball, Tennis}
2) Identify the set of sports that Mia enjoys.
{Basketball, Cross Fit, Hockey, Softball, Tennis}
3) Identify the set of sports that Mike or Ed enjoy.
{Badminton, Basketball, Baseball, Boxing, Golf, Softball, Tennis, Wrestling}
4) Identify the set of sports that Mike, Ed, and Mia all enjoy.
{Basketball}
5) Identify the most liked sport.
Basketball!!! 

11. 4.3 Intersection and Union of Sets
Summarize Notes
Read section 4.3
Homework
Worksheet