Download Review

Chapter 9
In the beginning


Set: Collection of Objects
Examples:



Arnold’s “set” of cars
Nirzwan’s “set” of borrowed credit cards
Elements: those objects that are in a set

Examples
• The cars and the credit card #’s

Roster Method: when you write a set by enclosing the
elements in braces


A={1,2,3}
Note: Typically, a set is designated by a capital letter
• Example

B
After the beginning

Empty set (aka: null set)– Set with nothing in it

Also uses { } sometimes
• Ex: The number of Mansions I own
• X={}


Union: (U) Shows a set that has the elements of 2
other sets.
What is A U B given A = {1,2,3,4} B = {3,4,5,6}


A U B = {1,2,3,4,5,6}
Note: only list the elements that A and B have in common
once!
More of the beginning

Intersection
What two
or more sets have in
common
 Find A
B given A =
{1,2,3,4} B={3,4,5,6}
 A
B = {3,4}
Set Builder
 Set
Builder notation: another way to
represent sets
 2 parts to this

1. What you want to represent
• Ex: all integers less than 8

 x<8
2. What numbers you can use
• Ex integers  x
all integers
• Other words that can be used instead of integers

Positive or negative integers, real numbers, positive or
negative real numbers, imaginary numbers!
Inequality

Ever see these before?
 <, > , 


These are symbols of inequality!

Examples are 4 > 2, 3x
87 and Nirzwan
getting drug-searched outside of Burley!
Graphing an inequality in 1-D

Draw a number line appropriate for the
problem
 For less than or greater than use a
parenthesis bracket, for less than or equal to
or greater than or equal to, use a square
bracket


Ex: x>1,

Ex: x>5 U x < 0
x
-3
U Try Its

1 through 11?
Homework
 Section
9.1 – 1-41 every other odd