Monday, March 7, 2011

Sinthetic Division

Using the Difference Quotent


Examples of Annual Rates and Ivory Aging

Kahn Academy

Laws of Exponents!

Logarithms!

Kahn Academy

Formulas!

Completing the Square

 Kahn Academy

Polynomial Functions

A polynomial function is one that can be written in the form
anx + an-1xn-1+…+a3x3+a2x2 + a1x+ a0
Where n is an non negative integer, x is a variable, and each of  a0,a1,a2,…an is a constant called a coefficient. 

 Rational Functions:
Find the domain of each rational function
1) f(x) = 1/x2
The domain of  f(x) = 1/x2 is the set of all real numbers except x = 0 because the denominator is 0 when x=0, making the fraction undefined
2) g(x) = x2 + 3x + 1/x2-x-6
The domain of g(x) = x2 + 3x + 1/x2-x-6 is the set of all real numbers except the solutions of x2-x-6=0. Because x2-x-6 factors into (x+2)(x-3), the solutions to x2-x-6=0 are x=-2 and x=3. Therefore, the domain of g is the set of all real numbers except x = -2 and x=3



 Real Functions:


Synthetic Division:

Inequalities

Inequalities
-Range of values for a solution.

Solving a compound linear inequality:

Example:

2<3x+5<2x+11


A solution of 2<3x+5<2x+11 is any number that is a solution of both of the following inequalities.
2<3x+5 and 3x+5 <2x +11
each of these inequalities can be solved by the principles listed above.

2 - 5 <3x       3x - 2x< 11- 5
-3<3x             x<6
-1<x

the solutions are all real numbers that satisfy both -1<x and x<6, that is -1<x<6. Therefore, the solutions are the numbers in the interval [-1,6).

Example:
 4 < 3-5x<18
When a variable appears only in the middle of a compound inequality the process can be streamlines by performing any operation on each part of the compound inequality.
4<3-5x<18
1<-5x<15
-1/5> x > -3
Intervals are usually written from the smaller to the larger, so the solution to the compound inequality is -3<x<-1/5
The solution of a compound inequality is the interval (-3,-1/5)

Kahn Academy:
http://www.khanacademy.org/video/algebra--solving-inequalities?playlist=Algebra
http://www.khanacademy.org/video/quadratic-inequalities?playlist=Algebra

Arithmetic and Geometric Sequences

-An arithmetic sequence has a constant difference and can be expressed as a line.
-A geometric pattern is a not linear, it is exponential.

Arithmetic Sequence:
In an arithmetic sequence {Un}
Un=Un-1+d
And for some constant d and all n>2

Example:
If {Un} is an arithmetic sequence with U1= 3 and U2 = 4.5 as its first two terms,
a)      a)  find the common difference
b)     b)  write the sequence as a recursive function
c)     c) give the first seven terms of the sequence
Solution:
A)     a) the sequence is arithmetic and has a common difference of U2-U1 = 4.5 - 3 = 1.5
B)      b) the recursive function that describes the sequence is U1 = 3 and Un-1 + 1.5 for n>2
C)     c) the first seven terms are 3, 4.5, 6, 7.5, 9, 10.5 and 12

Geometric Sequence:


In a geometric sequence {Un}
Un=RUn-1
For some U1 and some nonzero constant r and all n>2

 Example:
Is the following sequence geometric? If so, what is the common ratio? Write each sequence as a recursive function.
{3,9,27,81...}

The sequence is geometric with a common ratio of 3.
U2/U1 = 9/3  = 3
U3/U2 = 27/9 = 3
U4/U3 = 81/27 = 3

Because each term is obtained by multiplying the precious term by 3, the sequence may be denoted as a recursive function

Using Quadratic Formula and Completing the Square

Ax^2 + Bx + C = 0
x^2 +( b/a)x = -(c/a)

1.    1.    x^2 +(b/a) + (b/a)^2 = (b/2a)^2 – (c/a)
2.    2,    (x + (b/2a)^2) = (b/2a)^2 – (c/a)
3.   3.    x +(b/2a) = + or -   (b^2/4a^2)-(c/a)
4.   4.    x = + or - Square Root      b^2/4a^2 – c/a
5.   5.    x = -b/2a + or - Square Root    b^2-4ac/4a^2
6.  6.     x = -b/2a + or -  Square Root     b^2-4ac/2a
7.  7.     x = -b + or - Square Root    b^2 – 4ac/2a