Starting with GeomLab
When you start GeomLab (by clicking on the Big Green Arrow), you may be asked for permission to run an application that has been signed by a "Thawte Freemail Member". If you click the link and examine the attached certficate, you will find that it is associated with Mike Spivey's e-mail address. After you give permission, a window appears that looks like this:
This window has two areas for text. In the small, lower area,
you can type an expression like "2+3"; then
either hold down the Shift key and press the
Return key, or click with the mouse on the
Go button at the right. (Pressing just
Return in its own simply inserts a newline into the
expression). GeomLab shows your
expression in the upper area, followed by the value of the expression,
like this:
All the expressions you type are added to the upper window, and you can use the scroll-bar at the right to look at the entire history of your session of work.
At its simplest, GeomLab can be used as a kind of calculator,
showing the value of each expression that you enter. But
expressions in GeomLab don't always have numbers as their values; some
expressions evaluate to pictures. For example, the constant
man has as its value a stick figure of a man:
GeomLab's response shows that the value of man is a
picture, which is represented by
"<picture>" in the list of expressions
and values. But as well as showing this text, GeomLab also makes
a new window appear that shows the picture itself:
Most of the interesting expressions and programs you will write as part of this activity will have pictures as their values.
You are now ready to begin work on the first worksheet.