Texas Instruments TI-82 User Manual - Page 30

Entering Expressions and Instructions On the TI.82, you can enter expressions, which return a value, in most places where a value is required. You enter instructions, which initiate an action, on the Home screen or in the program editor (Chapter 13). Expressions An expression is a complete sequence of numbers, variables, functions, and their arguments that evaluate to a single answer. On the TI.82, you enter an expression in the same order that it normally is written. For example, pR2 is an expression. Expressions can be used on the Home screen to calculate an answer. In most places where a value is required, expressions may be used to enter a value. Entering an Expression To create an expression, enter numbers, variables, and functions from the keyboard and menus. An expression is completed when you press Í, regardless of the cursor location. The entire expression is evaluated according to EOS rules (page 1.20), and the answer displayed. Most TI.82 functions and operations are symbols with several characters in them. You must enter the symbol from the keyboard or menu, not spell it out. For example, to calculate the log of 45, you must press « 4 5. You cannot type in the letters L O G. (If you type LOG, the TI.82 interprets the entry as implied multiplication of the variables L, O, and G.)  Calculate 3.76 ÷ (-7.9 + ‡5) + 2 log 45. 3.76 ¥ £ Ì 7.9 à y ã‡ä 5 ¤ à 2 « 45 Í Multiple Entries on a Line To enter more than one expression or instruction on a line, separate them with a colon (:). They are all stored together in Last Entry (page 1.14). 1-6 Operating the TI.82