Chapter 2: Operating the Calculator 47
02OPERDOC TI
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89/TI
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92Plus (English) SusanGullord Revised:02/23/01 1:06 PM Printed:02/23/01 2:11 PM Page47 of 44
A variable name:
¦ Can use 1 to 8 characters consisting of letters and digits. This
includes Greek letters (but not p), accented letters, and
international letters. Do not include spaces.
− The first character cannot be a digit.
¦ Can use uppercase or lowercase letters. The names AB22, Ab22,
aB22, and ab22 all refer to the same variable.
¦ Cannot be the same as a name that is preassigned by the
TI-89 / TI-92 Plus. Preassigned names include:
− Built-in functions (such as abs) and instructions (such as
LineVert). Refer to Appendix A.
− System variables (such as xmin and xmax, which are used to
store graph-related values). Refer to Appendix B for a list.
Variable Description
myvar OK
aOK
Log Not OK, name is preassigned to the log function.
Log1 OK
3rdTotal Not OK, starts with a digit.
circumfer Not OK, more than 8 characters.
You can save any TI-89 / TI-92 Plus data type as a variable. For a list of
data types, refer to getType() in Appendix A. Some examples are:
Data Types Examples
Expressions 2.54, 1.25í6, 2p, xmin/10, 2+3i, (xì2)ñ, 2/2
Lists {2 4 6 8}, {1 1 2}
Matrices [1 0 0],
1 0 0
3 4 6
Character strings “Hello”, “The answer is:”, “xmin/10”
Pictures
Functions myfunc(arg), ellipse(x,y,r1,r2)
Storing and Recalling Variable Values
When you store a value, you store it as a named variable. You
can then use the name instead of the value in expressions.
When the TI-89 / TI-92 Plus encounters the name in an
expression, it substitutes the variable’s stored value.
Rules for Variable
Names
Examples
Data Types