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Tuesday, April 26, 2011

Algebra (Period 1)

Unions, Sets & Intersections 9-1

Conjunctions & Disjunctions 9-2

Conjunction = and --> the graph is an intersection ("yo") and inequality looks like our domains and ranges on our projects
EXAMPLE: 5 < x < 10 
open dots; between 5 and 10 is colored in 

Disjunction = or --> graph will go opposite ways ("dorky" dancer) and inequality looks like this:

x < -2 OR x > 4

open dots; one arrow goes right at 4 and the other arrow goes left at -2

Equations and Absolute Value 
1 VARIABLE
 9-3
Solve the equation twice - Once with the solution positive and once with it negative

I2x - 4I = 10

Solve it twice:

2x - 4 = 10 or 2x - 4 = -10

x = 7 or x = -3


If there is a term on the same side of the equation as the absolute value, move that to the other side of the equation first 
(just like we did with radical equations!) 
Then solve twice.


REMEMBER THAT THE SOLUTION GIVEN CANNOT BE NEGATIVE (the null set)




Inequalities and Absolute Value 
1 VARIABLE
 9-4
There are 2 possible types of inequalities - less than and greater than

For less thAND:

These are conjunctions and so you solve it twice and the solution ends up between them

I3xI < 15 is equal to -15<3x<15 
so x is greater than -5 and less than 5 
For greatOR than:

These are disjunctions and are solved twice with the solution infinitely in different directions

I3xI >15 is equal to 3x < -15 and 3x > 15


1 comment:

nicknjg said...

This resource is great for people like me... I am out a lot and so are some other kids who struggle to get by. In some classes it is really easy to catch up, but math is one subject that is difficult to learn when gone. Your notes give each of the notes we missed with your own explanations and tricks... This is great! I have gone over these notes because I did not have my spiral notebook so i couldn't look back at the quadratic formula (this was one of the first nights we got the formula). This helped me a lot.
-Nicole G. Period 1 Algebra