2. Set and Element
Set – a collection of things, put inside a
bracket
Ex: A = {Alabama, Alaska, Arizona}
Element – a thing in the set
Alabama is an element of A
Notation: Alabama ∈ A
3. Subset
A is a subset of B, if every element in A is also in
B.
Ex: A = {1, 2, 3}; B = {1, 2, 3, 4, 5}
Notation: A ⊂ B
4. Quiz 1.1.1
Let X = {a, b, c}. Which set is a subset of X?
A. {a, b, c, d}
B. {Kilroys, Nicks, Brothers}
C. {a, b}
5. Quiz 1.1.1
Let X = {a, b, c}. Which set is a subset of X?
A. {a, b, c, d}
B. {Kilroys, Nicks, Brothers}
C. {a, b}
Answer: C
6. Union, Intersection
Union of sets is a set which include all elements
from each set, without repeats.
Ex: Let A = {1, 2, 3}, B = {1, 3, 5}
A U B = {1, 2, 3, 5}
Intersection of sets is a set which include only
common elements from each set.
Ex: A ∩ B = {1, 3}
7. Quiz 1.1.2
Let A = {a, b, c}, B = {c, d, e}.
Which of the following is A U B?
A. {a, b, c, d, e, f}
B. {a, b, c, d, e}
C. {a, b, c, c, d, e}
8. Quiz 1.1.2
Let A = {a, b, c}, B = {c, d, e}.
Which of the following is A U B?
A. {a, b, c, d, e, f}
B. {a, b, c, d, e}
C. {a, b, c, c, d, e}
Answer: B
9. Universal Set, Complements
A Universal set is a set which include all elements
being considered in the problem.
Ex: Considering days of the week,
U = {Mon, Tue, Wed, Thu, Fri, Sat, Sun}
Complement of a set is a set which include only
elements NOT in the original set.
Notation: A’ is complement of A
Ex: Let A = {Mon, Wed, Thu}
A’ = {Tue, Fri, Sat, Sun}
10. Quiz 1.1.3
Let U = {1, 2, 3, 4, 5}, A = {2, 3}. Which of the
following is A’?
A. {1, 4, 5}
B. {2, 3}
C. {1, 2, 3}
11. Quiz 1.1.3
Let U = {1, 2, 3, 4, 5}, A = {2, 3}. Which of the
following is A’?
A. {1, 4, 5}
B. {2, 3}
C. {1, 2, 3}
Answer: A
12. Summary
Definitions:
Set
Element
Subset
Universal set
Unions/Intersection/Complements of set
13. Features
27 Recorded Lectures
Over 116 practice problems with recorded solutions
Discussion boards/homework help
Visit finitehelp.com to find out more
For special offers and additional content...
Follow us on twitter @finitehelp Become a fan on Facebook