Оценок - 4, средний балл: 3.8
(
)
)
|
Фрагмент инструкции
(Most statistics registers are exceptions — they're always shown as decimal numbers.) Display Rules The fraction you see may differ from the one you enter. In its default condition, the calculator displays a fractional number according to the following rules. (To change the rules, see "Changing the Fraction Display" later in this chapter.) ■ The number has an integer part and, if necessary, a proper fraction (the numerator is less than the denominator). ■ The denominator is no greater than 4095. ■ The fraction is reduced as far as possible. Examples: These are examples of entered values and the resulting displays. For comparison, the internal 12-digit values are also shown. The A and ▼ annunciators in the last column are explained below. 5-2 Fractions Entered Value Internal Value Displayed Fraction 23/8 2.37500000000 2 3/3 14 15/32 14.4687500000 14 15/32 54/12 4.50000000000 4 1/2 6 18/5 9.60000000000 3 3/5 34/12 2.83333333333 2 5/6 ▼ 15/8192 0.00183105469 0 7/3823 ▲ 12345678 l2345/3 (Illegal entry) A 16 3/16384 (Illegal entry) A Accuracy Indicators The accuracy of a displayed fraction is indicated by the A and ▼ annunciators at the right of the display. The calculator compares the value of the fractional part of the internal 12-digit number with the value of the displayed fraction: ■ If no indicator is lit, the fractional part of the internal 12-digit value exactly matches the value of the displayed fraction. ■ If ▼ is lit, the fractional part of the internal 12-digit value is slightly less than the displayed fraction — the exact numerator is no more than 0.5 below the displayed numerator. ■ If A is lit, the fractional part of the internal 12-digit value is slightly greater than the displayed fraction — the exact numerator is no more than 0.5 above the displayed numerator. This diagram shows how the displayed fraction relates to nearby values — A means the exact numerator is "a little above" the displayed numerator, and ▼ means the exact numerator is "a little below". ▼0 7/16 0 7/16 A0 7/16 6 / 6.5 / 7 / ^.5/ ®/ /16 /16 /16 /16 /16 (0.40625) (0.43750) (0.46875) Fractions 5-3 This is especially important if you change the rules about how fractions are displayed. (See "Changing the Fraction Display" later.) For example, if you force all fractions to have 5 as the denominator, then 2/3 is displayed as 0 3/5A because the exact fraction is approximately 3.3333/5, "a little above" 3/5. Similarly, -2/3 is displayed as _0 3/5 A because the true numerator is "a little above" 3. Sometimes an annunciator is lit when you wouldn't expect it to be. For example, if you enter 2 2/3, you see 2 2/3A, even though that's the exact number you entered. The calculator always compares the fractional part of the internal value and the 12-digit value of just the fraction. If the internal value has an integer part, its fractional part contains less than 12 digits — and it can't exactly match a fraction that uses all 12 digits. Longer Fractions If the displayed fraction is too long to fit in the display, it's shown with ... at the beginning. The fraction part always fits — the ... means the integer part isn't shown completely. To see the integer part (and the decimal fraction), press and hold 1131 I SHOW I. (You can't scroll a fraction in the display.) Example: Keys: 14 l_£ fr^ I SHOW I A m fvfE^n A Display: ...2604 888/3125 1202604.28416 ...2604 888/3125 R= ...2604 888/3125 0 Description: Calculates e14. Shows all decimal digits. Stores value in A. Views A. Clears x. Changing the Fraction Display In its default condition, the calculator displays a fractional number according to certain rules. (See "Display Rules" earlier in this chapter.) However, you can change the rules according to how you want fractions displayed: ■ You can set the maximum denominator that's used. 5-4 Fractions ■ You can select one of three fraction formats. The next few topics show how to change the fraction display. Setting the Maximum Denominator For any fraction, the denominator is selected based on a value stored in the calculator. If you think of fractions as a b/c, then /c corresponds to the value that controls the denominator. The /c value defines only the maximum denominator used in Fraction-display mode — the specific denominator that's used is determined by the fraction format (discussed in the next topic). ■ To set the /c value, press n li3| (^, where n is the maximum denominator you want. n can't exceed 4095. This also turns on Fraction-display mode. ■ To recall the /c value to the X-register, press 1 li3| (^. ■ To restore the default value or 4095, press 0 1131 17^. (You also restore the default if you use 4095 or greater.) This also turns on Fraction-display mode. The /c function uses the absolute value of the integer part of the number in the X-register. It doesn't change the value in the LAST X register. Choosing a Fraction Format The calculator has three fraction formats. Regardless of ...