2. • Describe and define union and intersection of sets.
• Find the union or intersection of sets.
• Use Venn diagrams to represent the union and intersection of sets.
By the end of this lesson, you will...
4. Answer the follow-up questions:
1. If we will combine all their favorite
subjects, what are they?
2. Is there a subject that they both like?
What is this?
3. Do you have your favorite subjects too?
11. Universal set of Animals:
E = Everything = { Fish, Eels, Platypus, Penguins, Eagles, Bats }
12. Intersection of Sets
“Water Animals” and “Two Legged Animals” .
When we do this, we find that Penguins belong in both groups:
E = Everything = { Fish, Eels, Platypus, Penguins, Eagles, Bats }
Water Animals={Fish, Eels, Platypus, Penguin}
Two Legged Animals = {Eagles, Bats, Penguins }
13.
14. Union of Sets
The union of two sets is everything that
is contained within the two circles
joined together.
15.
16. The cardinality of a set is the number of
elements contained in that set.
a. Who are the personalities given in Activity 1 in Set A? in Set B?
b. Who is common in both sets? Why?
c. How will you differentiate union and intersection of sets?
d. Can you give your own real-life examples of these sets?
17. Try this
Given: A = {a,e,i,o,u}
B = {a,b,c,d,e}
Find:
1. A ∩ B
2. A U B
These are diagrams that make use of geometric shapes to show relationships between shapes
We are going to use a Venn diagram to divide these animals into the following two sets:
This means that on our Venn Diagram, we will need to have two overlapping circles, so that we can put Penguins inside both circles.
It is the combined total of the two sets, where each item is only listed once.
For our Venn Diagram of Two Legged Animals and Water Animals, we have:
{ Two Legged Animals } Union { Water Animals } ={ Fish, Eels, Platypus, Penguins, Eagles, Bats }
Union is often written using a big “U” symbol, or the word “OR”
