Sunday, March 18, 2012

How Do We Simplify Radicals?

Step 1: Find all the " Prime Factors" starting with the smallest Prime 
Step 2: Rewrite using square Notations
Step 3: Separate square root notations 


Example: Simplify .

180 = 2·  90 = 2· 2· 45 = 2· 2· 9· 5 = 2· 2· 3· 3· 5
Therefore,
 = 2· 3 = 6.
here is a video to help you understand better

Thursday, March 15, 2012

How do we Factor the difference of squares?

This expression is called a difference of two squares. 










The factors of          are and     



Example 1:
Factor:   x2 - 9Both x2 and 9 are perfect squares.  Since subtraction is occurring between these squares, this expression is the difference of two squares.
What times itself will give x?  The answer is x.
What times itself will give 9 ?  The answer is 3.
These answers could also be negative values, but positive values will make our work easier.
The factors are (x + 3) and (x - 3).
Answer:  (x + 3) (x - 3)  or   (x - 3) (x + 3)   
(order is not important)


Here is a video to help you understand better....

How do we divide polynomials?

 Simplify (2x + 4)/2

Factor out the common factor from the top and bottom, and then cancel off:



X = 2




Here is a video to help explain how to divide polynomials:

Monday, March 12, 2012

How do we identify all the Elements of a Parabola?

When you have the formula to graph a Parabola you need to be able to understand what it stands for/ says....


                      y = ax2 + bx + c
The  A for how wide or how narrow the parabola will be.
The   B stands for the line of symmetry
The  C tells you if its will be facing up or will be facing down.( If a Parabola is facing down the C is negative but if its facing up then the C is Positive)




To find the axis of symmetry you use the formula......






          X  = -  B
                       
                  2A


Roots are where and when the parabola touches the X-axis 

How do we Graph Parabolas?


Graphing the Parabola y = ax2 + bx + c


1.    Determine whether the parabola opens upward or downward.


                 a.    If a is positive, it opens upward.
                b.    If a negative, it opens downward.


2.    Determine the vertex.
             a.    The x-coordinate is .
                 b.    The y-coordinate is found by substituting the x-coordinate, from Step 2a, in the equation                                                     y = ax^2 + bx + c.


3.    Determine the y-intercept by setting x = 0.

by determining all the key features of the graph. That is, find the vertex, the x- and y-intercepts (if any), and additional points if needed. Find the domain and range of the function.
Opens upward since the coefficient of the x2 is positive  


4.    Determine the x-intercepts (if any) by setting y = 0, i.e., solving the equation 
       ax2 + bx + c = 0.


5.    Determine two or three other points if there are no x-intercepts.



For Example:

Graph  
Vertex:  and  So the vertex is (3, -4).
y-intercept:  The y-intercept is (0,5).
x-intercepts:
                            
The x-intercepts are (5,0) and (1,0).
        Points plotted on grid below:
 Then connect the points with a smooth curve.
Here is A video to help you understand better how to graph a Parabola.















































Sunday, March 4, 2012

How do we solve rational Proportions?

Solve...
                   k+4             K+9
                --------  =    --------
                     2                 3
Step 1 : multiply each side by a number to get a common denominator
          3  *  k+4             K+9  *3
                --------  =    --------
          3*      2                 3      *3
Step 2:  you cancel the  denominator  because their the same 
          
                 3k+12          2K+18
                --------  =    --------
                     6                6
Step 3: start to subtract, add , divide, or multiply to both sides to cancel out terms to get x by its self and to equal to a number

          3k + 12 = 2k +18
        -2k           -2k
                                         
          k + 12 = 18
             -12     -12
                                         
                 k = 6

How do we solve rational Expression?

Simplify the following Expression.....

                                                2                  3
                                            ------     -     -------
                                               A                  A^2
Step 1: Change fractions into equivalent fractions with a common denominator
                                      A *    2                  3
                                            ------     -     -------
                                   A*      A                  A^2
Step 2: add or subtract  numerators, keep the common denominator
                                                2                  3                    2A -  3
                                            ------     -     -------       =   ------------
                                              A^2                 A^2                A^2
Step 3:Simplify the resulting expression, cancelling common factor
                               2A -  3
                           ------------     ( because the expression does not  simplify any more this is your final answer)
                                 A^2