Basic Equations    Basic Graphing       Fractions

This page is designed to help you better understand, work with, and draw graphs.  Scroll down or use the links below to begin understanding graphing.  The coordinate plane and points Graphs of lines Quiz on Basic Graphing In the coordinate plane, or the rectangular coordinate system, the vertical y-axis and the horizontal x-axis intersect at a point called the origin. This section will help you better understand the coordinate plane and how to graph points on the plane. The origin's coordinates are (0,0). Points are named by an ordered pair.  Example:          (4,2) The first number in an ordered pair is the x-coordinate, and the second number listed is the y-coordinate.  Example:  When graphing, the coordinate plane will be labeled with "tick marks" denoting the scale.  Beginning at the origin, count along the x-axis scale until you find the tick mark labeled with the x-axis coordinate of your point, and then count along the y-axis scale until you find the tick mark labeled with the y-axis coordinate of your point.  That is the location of your point!  However basic this seems, it is a necessary skill for graphing lines and other equations. Back to Top  This section will help you to understand how to better graph linear equations. Linear equations can be graphed when in the form y = mx + b m equals the slope of the line. b equals the point where the line crosses the y-axis.  This is called the y-intercept. When graphing linear equations, "plugging in points" is a suggested method of solving the equations and putting them in a graphical format.  To plug in points, select an x-coordinate (be reasonable in the number you select for the x-coordinate) and put the x-axis coordinate in the equation in place of x.  Then solve the equation.  This will give you a y-value.  Put your chosen x-value and the y-value you solved for together, and you will have an ordered pair (a point) that you can graph.  Repeat this process about 4 or 5 times and then connect the points you have graphed.  The line you see will be the graph of a linear equation. 1.   Graph:   y = 2x + 1      Solution:        y = 2(0) + 1      y = 1      (0,1)   An x-coordinate of 0 was selected. The equation was solved for y. The resulting ordered pair is (0,1).      x | y      ---------      0 | 1      1 | 3      2 | 5      -1 |-1   The process described above repeated 4 times. The results are shown to the left in table form. The graph: Back to top  Take the Quiz on graphing linear equations.  (Very useful to review or to see if you've really got this topic down.)  Do it!