Transcript 1.1 & 1.2
1.1 – SETS AND SYMBOLS
Goals
SWBAT understand basic set notation and set
symbols
SWBAT solve simple sentences with a given
domain
SWBAT graph sets of numbers on a number line.
IMPORTANT DEFINITIONS
A set is a well-defined collection of objects.
Each object in the set is called an element.
Set notation uses braces.
Example:
1, 3, 8,13
WAYS TO SPECIFY A SET
1. List the names of its members within braces.
(roster)
Example:
1, 2, 3
2. A rule or description of its members.
Example:
all numbers greater than 1
3. By a graph. (Covered in 1.2)
COMMON SET SYMBOLS
Read as: “the set whose members are”
Meaning: a collection or set
Read as: “is a member of” or “is an element of”
Meaning: is in the collection or set
COMMON SET SYMBOLS
A B
Read as: “A is a subset of B”
Meaning: Every member of A is a member of B. For
every set A, A is a subset of A.
or
Read as: “the null set” or “the empty set”
The set that contains no elements. The empty set is
considered a subset of every set.
COMMON SET SYMBOLS
AB
Read as: “A is equal to B”
Meaning: A and B contain exactly the same elements
/
Read as: “is not”
Meaning: used with other symbols to show negation:
, ,
COMMON SET SYMBOLS
AB
Read as: “A intersect B”
Meaning: The set of elements belonging to both A and
B.
AB
Read as: “A union B”
Meaning: The set of elements in at least one of the
given sets.
TRUE OR FALSE?
1 3
1 2, , , 4
2 3
TRUE OR FALSE?
3, 4,5 odd integers
TRUE OR FALSE?
1 1 1
0.25 , , 0,
2 4 3
TRUE OR FALSE?
real numbers integers
1.2 – OPEN SENTENCES AND
GRAPHS
DEFINITIONS
An
expression is a number, a variable, or a
sum, difference, product, or quotient that
contains one or more variables.
Examples: 7 9,
4 x
,
3
5 y 7 2,
4 12
DEFINITIONS
A variable
is a symbol, usually a letter, that
represents any of the members of a specified set. This
set is called the domain of the variable, and its
members are called the values
of the variable.
DEFINITIONS
A
mathematical
sentence is a group of
symbols that states a relationship between two
mathematical expressions. These can be either
true or false.
Examples:
3 2
, 1 2 17, 14 8 6
4 5
DEFINITIONS
An
open sentence is a mathematical sentence
that contains one or more variables. An open
sentence cannot be determined true or false
without knowing what value the variable
represents.
Examples:
x 7 4, m p 2m 5, h 93
DEFINITIONS
The values of the variable that make an open
sentence true are called the solutions of the
open sentence.
The
solution
set is the set of all solutions
that make the open sentence true.
To
solve an open sentence over a given
domain, find the solution set using this domain.
QUESTIONS 1-4: SOLVE THE OPEN SENTENCE
2,3,4,5
OVER THE DOMAIN
1.
2x 3 7
2.
8t 6t 2t
3.
n 1 is an integer
3
4.
y y 1
DEFINITIONS
A
real number is any number that is positive,
negative, or zero.
Subsets
of Real Numbers:
Natural Numbers:1,2,3,...
Whole
Numbers: 0,1,2,3,...
Integers:
...,3,2,1,0,1,2,3,...
It can be useful to graph the solution set of an
open sentence on a number line.
5. Graph each subset of the real numbers on a
number line.
a. Natural Numbers
b. Whole Numbers
c. Integers
GRAPH EACH SET OF NUMBERS ON THE
NUMBER LINE.
6.
3
5
,1, ,3
2
2
7. The set of integers that are multiples of 4.
SOLVE EACH OPEN SENTENCE OVER THE SET OF
POSITIVE INTEGERS AND GRAPH THE SOLUTION SET.
8.
25 y 9
9.
z 5
10.
2
2
h
2
Is an integer