View source for Basic Algebra/Lines (Linear Functions)/Slope of a Line

== Vocabulary ==

== Lesson ==
To understand the Cartesian Coordinate graph and how it works,
you must know how number lines work. A number line is a line of
numbers that streches infinitely on both sides.
The Negative numbers extend infinitely to the left and the Positive 
numbers go infinitely to the right. Zero sits right smack in the dead 
center of the line however long it might be. A cartesian coordinate 
graph is just two infinite number lines one vertical(the X-axis) and 
one horizontal(the Y-axis) on top of each other forming a cross with 
0 as the center point or Origin as it is called. The graph is also divided into 4 quadrants. these are numbered with Roman numerals.

http://commons.wikimedia.org/wiki/Image:2D_Cartesian_Coordinates.svg
 
However, for understandability's sake, this graph is usually 
shortened to -6 and + 6 on both the X and Y axis. Also, however, this graph is also ugly and not very user friendly. (Gridboard)

Now, how to determine the slope of a line: Let's pretend that we are
baking giant chocolate cookies for a bake sale. Right before you
start your Bake-O-Rama, You make three of them. You figure you can
make two an hour. You also take inventory every hour like this:
                          <u>Hours Cookies</u>
                           0      (2x0)+3=3
                           1      (2x1)+3=5
                           2      (2x2)+3=7

== Example Problems ==
[[Image:quick graph.JPG]]

slope (m) = <math>\frac{y_2-y_1}{x_2-x_1}</math>

Using the points in the diagram above, x<sub>1</sub> and y<sub>1</sub> are both 2
and x<sub>2</sub> is 6 and y<sub>2</sub> is 4.  So we substitute each value into the slope equation.

== Practice Games ==
Sorry, none at this time!

== Practice Problems ==


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