1. Ch. 3 Vocabulary
10.) Union
11.) Intersection
12.) Disjoint sets

2. 3-8 Unions and Intersections of Sets
Algebra 1

3. UNION or U
The Union of 2 or more sets is the set that contains all elements of the sets.
A B
Venn Diagram
A U B 12

4. Intersection ∩
The Intersection of 2 or more sets is the set of elements that are common to every set.
A B
Venn Diagram
A ∩ B

5. Disjoint Sets
Disjoint sets have no elements in common. The intersection of disjoint sets is the empty set. { } or Ø
A B

6. Union and Intersection of Sets
Ex. 1)
P = { x| x is a whole number less than 5}
Q = { y| y is an even natural number less than 5}
a)Write sets P and Q below in roster form.
b)What is P ∪𝑄?
c.) What is P ∩𝑄?
c.) Draw a Venn Diagram representing P and Q.

7. Union & Intersection of Sets
Ex. 2) Let
A = {2, 4, 6, 8}
B = {0,2, 5,7 8}
C = { n| n is an odd whole number less than 10}.
2a.) What is A ∩𝐵?
2b.) What is A ∩𝐶?
2c.) What is C ∩𝐵?
2d.) What is A ∪𝐵?
2e.) Draw a Venn diagram for A, B and C.

8. Assignment