Texas Instruments TI86 User Manual - Page 51

Chapter 2: The CATALOG, Variables, and Characters 39 This chapter describes the first two data storage methods listed here. The other methods are described in the appropriate chapters. Storing Data to Variables On the TI-86, data can be stored to variables in several ways. You can: ♦ Use X to store a value to a variable. ♦ Use = to store an unevaluated expression to an equation variable. ♦ Use an editor's Name= prompt to store several types of data to a variable. ♦ Change TI-86 settings or reset defaults and memory to the factory settings. ♦ Execute functions that cause the TI-86 to store data automatically to built-in variables. The TI-86 has built-in variable names with specific purposes, such as equation variables, list names, statistical result variables, window variables, and Ans. You can store values to some of them. They are introduced in the appropriate chapters of this guidebook. Creating a Variable Name You can create your own variable name when you use X, =, or a Name= prompt to store data. When you create a user-created variable name, follow these guidelines. ♦ The user-created variable name can be from one to eight characters long. ♦ The first character must be a letter, which includes all CHAR GREEK menu items, as well as and ç from the CHAR MISC menu. ♦ A user-created variable name cannot replicate a TI-86 feature symbol or built-in variable. For example, you cannot create abs, because abs is the absolute value function symbol. You cannot create Ans, because it is already a built-in variable name. ♦ The TI-86 distinguishes between uppercase and lowercase characters in variable names. For example, ANS, Ans, and ans are three different variable names. Therefore, only Ans is a built-in variable name; ANS and ans can be user-created variable names.