Suppose you were told to locate "(5, 2)" (pronounced as "the point five two" or just "five two") on the plane. Where would you look? To understand the meaning of "(5, 2)", you have to know the following rule: The x-coordinate (the number for the x-axis) always comes first. The first number (the first coordinate) is always on the horizontal axis.
So, for the point (5, 2), you would start at the "origin", the spot where the axes cross: | |
...then count over to "five" on the x-axis: | |
...then count up to "two", moving parallel to the y-axis: | |
...and then draw in the dot: |
When plotting, remember that the first number is for the horizontal axis and the second number is for the vertical axis. You always go "so far over or back" and then "so far up or down".
- Plot the point (4, –5).
I will start at the origin: | |
...then I'll count over four units on the horizontal x-axis: | |
...then I'll count down five units paralell to the y-axis: | |
...and then I'll draw my dot: |
- Plot the point (–3, –1). Copyright © Elizabeth Stapel 2000-2011 All Rights Reserved
I'll start at the origin: | |
...then I'll count backwards three units along the x-axis: | |
...then I'll count down one unit parallel to the y-axis: | |
...and then I'll draw my dot: |
http://www.purplemath.com/modules/plane2.htm
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