Texas Instruments 83CML/ILI/U Guidebook - Page 49

Implied Multiplication Parentheses The TI.83 recognizes implied multiplication, so you need not press ¯ to express multiplication in all cases. For example, the TI.83 interprets 2p, 4sin(46), 5(1+2), and (2ä5)7 as implied multiplication. Note: TI.83 implied multiplication rules differ from those of the TI.82. For example, the TI.83 evaluates 1à2X as (1à2)äX, while the TI.82 evaluates 1à2X as 1/(2äX) (Chapter 2). All calculations inside a pair of parentheses are completed first. For example, in the expression 4(1+2), EOS first evaluates the portion inside the parentheses, 1+2, and then multiplies the answer, 3, by 4. Negation You can omit the close parenthesis ( ) ) at the end of an expression. All open parenthetical elements are closed automatically at the end of an expression. This is also true for open parenthetical elements that precede the store or display-conversion instructions. Note: An open parenthesis following a list name, matrix name, or Y= function name does not indicate implied multiplication. It specifies elements in the list (Chapter 11) or matrix (Chapter 10) and specifies a value for which to solve the Y= function. To enter a negative number, use the negation key. Press Ì and then enter the number. On the TI.83, negation is in the third level in the EOS hierarchy. Functions in the first level, such as squaring, are evaluated before negation. For example, MX2, evaluates to a negative number (or 0). Use parentheses to square a negative number. Note: Use the ¹ key for subtraction and the Ì key for negation. If you press ¹ to enter a negative number, as in 9 ¯ ¹ 7, or if you press Ì to indicate subtraction, as in 9 Ì 7, an error occurs. If you press ƒ A Ì ƒ B, it is interpreted as implied multiplication (AäMB). Operating the TI-83 1-23