HP 33s - Manual (Page 128)

8–6 Integrating Equations
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 )  
 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.
| H
1%2ª% Displays the current Equation.