HP 33s hp 33s_user's manual_English_E_HDPM20PIE56.pdf - Page 128

Specifying Accuracy The display format's setting (FIX, SCI, ENG, or ALL) determines the precision of the integration calculation: the greater the number of digits displayed, the greater the precision of the calculated integral (and the greater the time required to calculate it). The fewer the number of digits displayed, the faster the calculation, but the calculator will presume that the function is accurate to the only number of digits specified in the display format. To specify the accuracy of the integration, set the display format so that the display shows no more than the number of digits that you consider accurate in the integrand's values. This same level of accuracy and precision will be reflected in the result of integration. If Fraction-display mode is on (flag 7 set), the accuracy is specified by the previous display format. Interpreting Accuracy After calculating the integral, the calculator places the estimated uncertainty of that integral's result in the Y-register. Press [ to view the value of the uncertainty. For example, if the integral Si(2) is 1.6054 ± 0.0002, then 0.0002 is its uncertainty. Example: Specifying Accuracy. With the display format set to SCI 2, calculate the integral in the expression for Si(2) (from the previous example). Keys: Display: Description: { } 2 )   |H 1%2ª% Sets scientific notation with two decimal places, specifying that the function is accurate to two decimal places. Rolls down the limits of integration from the Z-and T-registers into the X-and Y-registers. Displays the current Equation. 8-6 Integrating Equations