SETS

1
SETS

• Definition, notation, operations

2
SETS - definition

• A set is a collection of objects
• Sets are represented by
• listing its members (elements) or by a
  descriptive process (may include set notation)

3
Sets-example 1

• A is the set of names of all Washington counties
  that begin with the letter S (descriptive)
• A Snohomish, Skamania, Skagit, Spokane,
  Stevens (list)

4
Sets- example 2

• B is the set of whole numbers between 5 and 11
  (descriptive)
• B x x is a whole number between 5 and 11
  (descriptive using set notation)
• B x x is a whole number such that 5 ltx lt 11
  (descriptive using set notation)
• B 6, 7, 8, 9, 10 (list)

5
SETS

• Empty Set is called the null set
• Represented by or Ø

6
SETS - Notation

• B all even whole less than 12
• B
• Bx xlt12 and x is even

7
SETS- Subset Notation

• C2, 4, 6 and D 2, 4, 6, 8,10

8
SETS- Operations on Sets

• Union of Sets A U B is the set that consists of
  all elements belonging either to A or to B or
  both
• Intersection of Sets is the set of all elements
  common to sets A and B

9
Complement of a Set

• The complement of a set A, is written A or
• and is the set of all elements in the universe,
  U, that are not in A