HP -32S Owner's Manual page 132

2 fR/sl S=0.7834 x = 2. Starts integrat
ing and produces the
result for Jff fit).
To complete the calculation, remember to multiply the value of the
integral by the constant (1/ir) outside the integral. (You could also in
clude this multiplication as part of the program.)
BH (T) 0.2239 Final result for /0(2).
Now calculate /0(3) with the same limits of integration. You don't
have to respecify the function (routine J), but you must respecify the
limits of integration (0, ir) since they were pushed off the stack by the
subsequent division by tt.
0 1ENTER IM*|
3.1416
X72.0000
Displays upper lii
HI SOLVE// | {/FN} T
Starts integration;
prompts for x.
3|R/S|
,T=-0.8170
Integral of fit).
1 0 0
-0.2601
Result for /0(3).
Example: Sine Integral. Certain problems in communications the
ory (for example, pulse transmission through idealized networks)
require calculating an integral (sometimes called the sine integral) of
the form
Si(t)
X'fr)*
Find Si(2).
Key in the following program to evaluate the function
fix) = (sinx) -5- x.*
*If the calculator attempted to evalutate this function at x = 0, the lower limitof integration,
an error (DIVIDE BY 8) would result. However, the integration algorithm normally does
not evaluate functions at either limit of integration, unless the endpointsof the interval of
integration are extremely close together or the number of sample pointsis extremely large.
130 8: Numerical Integration