Chapter Nine:  Inequalities and Absolute Value

Take notes on the following topics.
Algebra 1 Notes

Chapter Nine

Section 9.1

Section 9.2

Section 9.3

Section 9.4

Section 9.5

Section 9.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



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Section 9.1    Sets, Intersections, and Unions 

(Examples provided by Prentice Hall)

Part I: Set-Builder Notation

Write using (a) set-builder notation and (b) roster notation.

 
Example 1   the set C of whole numbers greater than 5
(a) C = {x | x is a whole number and x > 5}
(b) C = {6, 7, 8, ...}

Example 2 the set N of negative integers
(a) N = {x | x is an integer and x < 0)
(b) N = {–1, –2, –3, ...}

Part II: Intersection of Sets

Find the intersection of each pair of sets.

 
Example 1   Let U = {1, 3, 5, 7} and V = {7, 6, 5, 4}. Find U Ç V.
U Ç V = {5, 7}

Example 2 Let R be the set of reals and Q be the set of rationals. Find R  Ç Q.
R  Ç Q = Q, because every rational is a real.

Example 3 Let J = {1, 2, 3, 5, 7, 9} and K = {0, 2, 4, 6, 8}. 

Find J Ç K.
J Ç K = {2

Part III: Union of Sets

Find the union of each pair of sets.

 
Example 1   Let C = {0, 1, 2, 3} and D = {1, 3, 5}. Find C È D.
C È D = {0, 1, 2, 3, 5}

Example 2 Let R = {1, 3, 5}. Find R È R.
R È R = {1, 3, 5} = R

 

Take class notes.

Before starting your homework, rework the examples that are illustrated in this section of your textbook and the examples that I demonstrated in class. 

Then do your homework.

Write down questions (examples or concept that you do not understand).......then.............. Ask these questions in class.