Understanding
the Slope of a Line
The
purpose of this applet is to understand the notion of "the slope of
a line". Use this applet as follows:
 If you get
lost, look in the "MESSAGES" area, you will always be told what
to do next. Error messages will also be displayed there.
 Doubleclick
in the grid area to get a first point. Note that once you have selected
a point, its coordinates will appear on the left of the applet window,
under POINTS.
 Doubleclick
a second time to get a second point. Several things will then happen.
First, the coordinates of the new point will appear on the left
of the applet window, under POINTS. Then, the quotient rise / run
and the value of the slope will be displayed on the left of the
applet window, under SLOPE. Finally, the line through the two points
will be drawn as well as the triangle symbolizing the rise and the
run.
 You can now
click on either point and drag it along the line. You will see the
point move, the triangle will be redrawn, the coordinates of the
point being dragged will be updated. The slope should remain the
same.
 If you either
click outside the grid area, or try to drag anything other than
one of the point, an error message will be displayed.

