Department of Mathematics --- College of Science --- University of Utah

Mathematics 1010 online

What's the Point?

If you see this red text then unfortunately your browser does not support applets. You may have to enable Java, or use a different system.Click here to see a gif image of the applet that you should be seeing.

The applet on this page let's you draw and find points in the Cartesian Coordinate system.

Clicking on the Applet brings up a Control Window and a Drawing Window. To exit the program click again on the applet, or click on "Quit" in the Control Window. When using the applet for the first time click on "New" a few times to see a point in the Drawing Window and its coordinates in the Control Window. You can resize the Drawing Window if you wish.

Points lie at the intersections of the green grid lines in the Drawing Window and can be specified with one digit beyond the decimal point. Clicking elsewhere, or entering more digits, causes the point or its coordinates to be rounded.

You can use the software in five modes, selected by the menu shown in blue in control window::

Show Point. You enter numbers in the text fields of the control window and the corresponding point appears in the drawing window.
Show Coordinates. You click on a point in the drawing widow and its coordinates show up in the text fields of the Control Window.
Guess Point. You locate the point in the Drawing Window whose coordinates are given in the Control Window, and click on that point. If you guessed right the point will be drawn, if you are wrong nothing happens.
Guess Coordinates. You figure out the coordinates of the point drawn in the Drawing Window and enter them in the Control Window. If you are correct then the appropriate text field changes color, and your coordinate is displayed by it.
Examples. The software shows both the point and its coordinates. This is the default mode. See another point by clicking on "New" in the control window.

The Controls in the Control Window have the following effects:

Quit exits the software.
New computes a new random point.
Show answers the question for you if you wish.
The blue menu selects the appropriate mode as described above. The default is Examples and the initial point is the origin.
Quadrant toggles the specification of the quadrants on and off. The default is off.
A green background in the text fields indicates that the number in the field corresponds with point, a purple background indicates the number is missing or incorrect (or you have not yet pressed "Enter".) In some modes the system will not let you enter a number and replace your input with the actual coordinate or a blank space.