MATH 102
Intro to 2.1 – Set Concepts
Mathematician:
Notes 01.06.16
Key Vocabulary
A set is a collection of objects, which are called elements or members of the set.
Therefore, a set can be related to numbers but it does not have to be. Today we will discuss both math
examples and non-math examples. Just to make sure we are on the same page, we need to define a
few math related terms first.
Natural Numbers:
Whole Numbers:
Integers:
The following are the three ways to write a set.
I.
II.
III.
DESCRIPTION
ROSTER-FORM
SET-BUILDER NOTATION
We are going to cover a non-mathematical example and a mathematical example of each.
I.
Description
Ex 1:
Ex 2:
Write a description of the set containing Lake
Superior, Lake Michigan, Lake Huron, Lake Erie
and Lake Ontario.
Write a description of the set below.
Answer:
Answer:


A = 1,2,3, 4,5,6
What are those squiggly lines in example 2 known as?
II.
Roster Form
Ex 1: Express the following in roster form.
Ex 2:
Express the following in roster form.
Set L is the set of Great Lakes in North America.
Set A is the set of natural numbers greater than or
equal to 10.
Answer:
Answer:
What are those dots in example 2 known as?
III.
Set-Builder Notation
Example:
F =
{x
x is a insert condition here}
Ex 1: Express the following in set-builder notation.
Ex 2: Express the following in set-builder notation.
L = {Lake Superior, Lake Michigan, Lake Huron,
Lake Erie, Lake Ontario}
C = { 1, 2, 3, 4, 5 }
Answer:
Answer:
In order to really do work with sets, the set must be well-defined. Give an example of a well-defined
set and one that is not well-defined.
Ex:
well-defined
Ex:
not well-defined
We must also understand the difference between an infinite set and a finite set. Find an example of
each above.
Ex:
infinite
Ex:
finite