Thursday, September 15, 2011

Rules for Exponents

Whenever you multiply two terms with the same base, you can add the exponents.
When given a problem such as this: Simplify (x3)(x4) you must add the exponents, the powers given to the base numbers, giving you a final answer of x7 Adding the exponents when multiplying numbers with the same base is a rule.  
This is represented as: ( x m ) ( x n ) = x( m + n )              


Whenever you have an exponent expression that is raised to a power, you can multiply the exponent and power
When given a problem such as: Simplify (x2)4   
You must multiply the exponents together, resulting in the final answer: x8
This is represented as:  ( xm ) n = x m n

If you have a product inside parentheses, and a power on the parentheses, then the power goes on each element inside. For instance, (xy2)3 = (xy2)(xy2)(xy2) = (xxx)(y2y2y2) = (xxx)(yyyyyy) = x3y6 = (x)3(y2)3. Another example would be:

    [ x/y ]^2 = (x^2) / (y^2) 
This rule does NOT work if you have a sum or difference within the parentheses. Exponents, unlike multiplication, do NOT "distribute" over addition.


Anything to the power zero is just "1"


Law Example
x1 = x 61 = 6
x0 = 1 70 = 1
x-1 = 1/x 4-1 = 1/4


xmxn = xm+n x2x3 = x2+3 = x5
xm/xn = xm-n x6/x2 = x6-2 = x4
(xm)n = xmn (x2)3 = x2×3 = x6
(xy)n = xnyn (xy)3 = x3y3
(x/y)n = xn/yn (x/y)2 = x2 / y2
x-n = 1/xn x-3 = 1/x3

























Dimensions of Matrices

The dimensions of a matrix can be determined by it's rows and columns.
The rows of a matrix are the numbers listed horizontally.
The columns of a matrix are the numbers listed vertically.
 





When you look at a matrix, the way you determine it's                                                                               dimensions is by first looking at the rows. Then you look
at the columns. In the example shown, there are 2 rows 
and 2 columns, making this a 2 x 4 matrix. I know this
because looking at the numbers going across, there are
2 rows. Looking at the vertical numbers, there are 4
columns.

Difference between types of systems.



 There are three types of systems. These systems include Dependent, Independent, and Inconsistent.

 A dependent system is a system that has infinitely many solutions and they are all numbers.
Example:










 The graphs of the equations are the same.


An Independent system is a system with only one solution.
Example: 











The graphs of the equations are different and they intersect.

An Inconsistent system is a system that has no solution.









These lines are parallel. Because they never touch, there is no solution.