TI-89 Guide
TI 89- 109
Copyright © Houghton Mifflin Company. All rights reserved.
name before continuing. (See DELETING PROGRAMS OR OTHER INFORMATION FROM
THE TI-89.)
SYMBOLIC
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I get a number instead of a symbolic expression. What is wrong?
If you do not get a symbolic result, it is because the variable you are using as the input variable has
a number stored in it. That is, the variable is a defined rather than an undefined variable. The
variable you use for the input variable must be an undefined variable in order to obtain a symbolic
result. Refer to the top of page TI89-5 of this Guide for more information.
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Why is the symbolic result not correct when I am using several letters in the problem?
One reason may be that the TI-89 thinks one of the variables is a function. For instance, if you
have defined c as a function and in another problem want c to be a variable coefficient, you must
indicate this when typing the expression: If you do not type c*(x + 5), the TI-89 assumes that you
are evaluating the function c at the input value x +5 when you type c(x + 5).
