Illustrating Common Point Plotting Errors

You may manipulate the sliders only.

Keep your eye on Point A. That point is in color. The sliders a and b represent its x and y coordinates. You can slide those two sliders, and Point A will move accordingly.

Moving along with Point A will be three other points. They are your common mistakes to avoid.

Point B represents what happens when you switch the x and y coordinates -- that is, you plot the x as the "y" and the y as the "x." This is by far the most common mistake.

Point C represents what happens when you plot the x-coordinate on the wrong side of the x-axis.

Point D represents what happens when you plot the y-coordinate on the wrong side of the y-axis.

As you can see, it does matter how you handle the coordinates. These points were generally all different.

The x-coordinate represents left-right and works like the number line.

The y-coordinate represents down-up and works like a thermometer.

I recommend handling these alphabetically; do your x left-right first, then your y down-up second, and plot your point.

Darron Steele, Created with GeoGebra