Need help on Math Graphing

[Sun.Ice]

Yeah...I need help on some graphing right now. We just learned some today and I'm still confused.

When it comes to graphing, it says to graph linear equations using three points.

How do I work this out?

[Dante]

Well, you find the x and y cordinate, then you move along the x axis of your graph till you find that point's x cordinate and mark it and move along the y axis to you find the y cordinate of the point and mark it as well. Now you draw a perpendicular line through each of the points to their respective axis. They should make a crosshair like point somewheres on the graph... This is the said point which has the x and y cordinates discussed.

Now repeat the above for the other two points to create two other dots somewhere on the graph. If you put a ruler on the page, you should find that all three points make a straight line (for linear equations) and just draw a line through those three points.

Generally speaking you can choose any three points your heart desires, but why not make life easy and set your y=0 and solve for x for your first point, then set x=0 and solve for y for the second point (your y and x intercept). Of course, other points may be easier and you'll still have to figure out what value of x you want to plug in for the final point, but all of this is really up to you.

Your paper says that you have to have three points because two points define a line and three points are required to PROVE that it is a line. If three points make up a line, then technally the function is linear. However, if they do not, than the function is some higher order polynomial or or some other transcendential function. But you've already been told that it's linear so you don't have to worry. Have fun!

Pascal

[Ingemar]

Just be thankful that you don't have to do linear regressions... yet.