Modules for Differential Calculus

Maple Tutor

Part 5: What Maple remembers

1. Create a new region and type
   x:=15;
   Then press the SHIFT and RETURN keys together. This gives you a new line within the region and does not evaluate the current line. Now type
   7.3/2.5;
   Then press RETURN to evaluate both lines.
2. Go back into the region, delete the line
   x:=15;
   and press RETURN. In the new region, enter
   x;
   Notice that Maple still remembers that x has been assigned the value 15 -- even though that line no longer appears in the worksheet.

We have come to the second important fact about Maple. (Ending a computation line with a semicolon or colon was the first.) Maple remembers what has been entered in the order it was entered.

• It doesn't matter what is currently in the worksheet, nor the order things appear in that worksheet. You may have assigned a value, erased the assigning command line, and forgotten about it. But Maple remembers. If you use x later, assuming it is an unassigned variable, strange things will happen.
• If variables are assigned new values, formulas using those variables acquire new values as well.

Last modified: June 23, 1997