Texas Instruments TI-84 PLUS Guidebook - Page 19

Entering an Expression To create an expression, you enter numbers, variables, and functions using the keyboard and menus. An expression is completed when you press Í, regardless of the cursor location. The entire expression is evaluated according to Equation Operating System (EOS™) rules, and the answer is displayed according to the mode setting for Answer. Most TI-84 Plus functions and operations are symbols comprising several characters. You must enter the symbol from the keyboard or a menu; do not spell it out. For example, to calculate the log of 45, you must press « 45. Do not enter the letters L, O, and G. If you enter LOG, the TI-84 Plus interprets the entry as implied multiplication of the variables L, O, and G. Calculate 3.76 P (L7.9 + ‡5) + 2 log 45. 3 Ë 76 ¥ £ Ì 7 Ë 9 Ã y C 5 ¤ ¤ Ã 2 « 45 ¤ Í MathPrint™ Classic Multiple Entries on a Line To enter two or more expressions or instructions on a line, separate them with colons (ƒ [:]). All instructions are stored together in last entry (ENTRY). Entering a Number in Scientific Notation 1. Enter the part of the number that precedes the exponent. This value can be an expression. 2. Press y D. â is pasted to the cursor location. 3. Enter the exponent, which can be one or two digits. Note: If the exponent is negative, press Ì, and then enter the exponent. When you enter a number in scientific notation, the TI-84 Plus does not automatically display answers in scientific or engineering notation. The mode settings and the size of the number determine the display format. Functions A function returns a value. For example, ÷, L, +, ‡, and log( are the functions in the example on the previous page. In general, the first letter of each function is lowercase on the TI-84 Plus. Most functions take at least one argument, as indicated by an open parenthesis following the name. For example, sin( requires one argument, sin(value). Chapter 1: Operating the TI-84 Plus Silver Edition 12