HP Forum Archive 19

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integrating on the HP35s Message #1 Posted by ezoob on 15 July 2009, 3:38 p.m. I'm an old HP15c user and I'm used to integrating by entering a program with a label and just integrating the program. I just bought a 35s, and I can't integrate on it the same way as with my 15c. When I try to integrate a program it prompts for an integration variable. How can I just integrate the program without entering an "equation" specifically? Is there a way I can do it like I used to on my 15C? Thnx in advance.

Re: integrating on the HP35s Message #2 Posted by Gene Wright on 15 July 2009, 3:55 p.m., in response to message #1 by ezoob Try the learning modules found here: Numeric integration on the 35s And, the 35s manual has a rather large section on integrating. Reading it is usually a good first step. ;-) All of the 35s modules can be found on this page: All 35s modules

Re: integrating on the HP35s Message #3 Posted by ezoob on 15 July 2009, 4:14 p.m., in response to message #2 by Gene Wright I read the manual. The section on integrating programs states on page 15-7: "Integrating a Program In chapter 8 you saw how you can enter an equation (or expression) — it's added to the list of equations — and then integrate it with respect to any variable. You can also enter a program that calculates a function, and then integrate it with respect to any variable. This is especially useful if the function you're integrating changes for certain conditions or if it requires repeated calculations." My question is: Can the calculator still integrate the program without me having to specify a variable? i.e. can it integrate the way my HP15C does, without having to specify a variable?

Re: integrating on the HP35s Message #4 Posted by Jeff Kearns on 15 July 2009, 6:12 p.m., in response to message #3 by ezoob You must specify a variable, but so what? It is 'one' line of programming and one keystroke during integration. And it's no problem at all once you get the hang of it. It is not much different from the 15C and can be mastered very quickly. Here is a simple example: Integrate 5x^2-3, from x=0 to x=2. (The answer is 7.33) On the 15C, you would write a simple program: 001 LBL 1 002 x^2 003 5 004 * 005 3 006 - 007 RTN Then you enter your limits of integration, 0 ENTER 2, and Integrate whatever program label contains the equation. On the 35s, the procedure is as follows: Write a program with the same equation as above, but call it LBL I as an example. Here goes... I001 LBL I I002 INPUT X I003 x^2 I004 5 I005 * I006 3 I007 - I008 RTN Then press LS FN= 'I' to specify the program label to be executed/integrated, enter the limits of integration as per the 15C, and Integrate 'X'. That's all there is to it. Jeff Edited: 15 July 2009, 6:19 p.m.

Re: integrating on the HP35s Message #5 Posted by ezoob on 15 July 2009, 6:24 p.m., in response to message #4 by Jeff Kearns Thank you both. That answers my question. Thanks esp for the example.

Re: integrating on the HP35s Message #6 Posted by Karl Schneider on 16 July 2009, 1:26 a.m., in response to message #3 by ezoob "ezoob" -- Integration on the HP-32S, HP-32SII, HP-33s, and HP-35s requires that a single-letter storage location be specified as the dummy variable of integration. Unlike the HP-34C, HP-15C, and HP-41 Advantage Pac, variables are passed to the user by register, not through the stack. Philosophy of implementation is discussed in my MoHPC article concerning SOLVE/INTEG on RPN-based models: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=556 -- KS

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