For advanced information – HP 15c User Manual
Page 258
258 Appendix E: A Detailed Look at
f
If any other program line is displayed, return to Run mode
and single-step (Â) through the program until you
reach a n
instruction (keycode 43 32) or line 000 (if
there is no n).
(Be sure to hold the  key down
long enough to view the program line numbers and
keycodes.)
3. Press | K to view the current approximation. If you want to
continue calculating the final approximation, press − +
¦. This refills the stack with the current x-value and restarts
the calculator.
For Advanced Information
The HP-15C Advanced Functions Handbook explores more esoteric aspects
of f and its applications. These topics include:
Accuracy of the function to be integrated.
Shortening calculation time.
Calculating difficult integrals.
Using f in Complex mode.