beautypg.com

Texas Instruments TITANIUM TI-89 User Manual

Page 252

background image

Symbolic Manipulation

252

Infinite recursions can occur when you define a substitution variable in terms of
itself.

When you enter a substitution that causes an infinite recursion:

Internally, an expression is sorted according to the automatic simplification rules.
Therefore, products and sums may not match the order in which you entered them.

-

An error message is displayed.

-

When you press

N, an error is

shown in the history area.

-

As a general rule, you should
substitute for a single variable.

sin(x)|x=x+1

Substitutes sin(x+1), sin(x+1+1),
sin(x+1+1+1), etc