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HP Forum Archive 21

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HP Prime: Integrate Won't Integrate
Message #1 Posted by James Williams on 11 Nov 2013, 11:58 a.m.

1. In CAS mode, int(x^2) returns 64*x instead of the correct x^3/3. Nearly every other integral is incorrect also. For example int(sin(x)) returns SIN(8)*x. (But diff(x^2) correctly returns 2*x.)

2. Also, the CAS menu line has only the Sto and simplif tabs, not the Math, CAS, App, Catlg, and OK tabs as shown in the user's guide. How can I get them back?

Resetting with On+Symb doesn't fix it (nor does inserting a needle in the reset hole on the back of the calculator). Restoring to factory settings with On+Apps+Esc does nothing whatsoever.

Other functions are starting to go haywire also. I am getting many reboots. For example, pressing Apps-->Geometry makes the calculator reboot every time.

      
Re: HP Prime: Integrate Won't Integrate
Message #2 Posted by Mark Hardman on 11 Nov 2013, 12:05 p.m.,
in response to message #1 by James Williams

James,

You have assigned a value of 8 to x.

Issue:

purge(x)
And try again.

            
Re: HP Prime: Integrate Won't Integrate
Message #3 Posted by James Williams on 11 Nov 2013, 1:15 p.m.,
in response to message #2 by Mark Hardman

Mark, thank you. That worked. The nonsense answers now make sense given that x=8. (But then diff(x^2) should have returned 0, not 2*x.) How can I purge all variables to make sure none of the rest of them are set to something without my knowledge?

                  
Re: HP Prime: Integrate Won't Integrate
Message #4 Posted by Mark Hardman on 11 Nov 2013, 1:21 p.m.,
in response to message #3 by James Williams

In CAS mode, press Shift-Clear (on the Esc key).

                        
Re: HP Prime: Integrate Won't Integrate
Message #5 Posted by Michael de Estrada on 11 Nov 2013, 1:28 p.m.,
in response to message #4 by Mark Hardman

That will clear everything, including the history. Just press Vars and see if there is a soft key named CAS to the immediate right of Home. If not, then there are no user defined variables remaining. If it is present, then you can delete any of them by selecting them and using the backspace. Also, you can still have separate User variables with the same name that can contain values and affect the CAS results. Those must be deleted from the Vars User menu.

Edited: 11 Nov 2013, 1:29 p.m.

                  
Re: HP Prime: Integrate Won't Integrate
Message #6 Posted by Joe Horn on 11 Nov 2013, 10:18 p.m.,
in response to message #3 by James Williams

Quote:
How can I purge all variables to make sure none of the rest of them are set to something without my knowledge?
One way to delete all the CAS variables only, without changing anything else, is the 'restart' command. Just type restart and press Enter. It will nicely return an array of the names of all the variables that it just purged (if any).

Warning: User-defined CAS functions are considered CAS variables, and are purged by 'restart'. User variables, and user-defined functions created by the Define button, are not purged by 'restart'.

      
Re: HP Prime: Integrate Won't Integrate
Message #7 Posted by Michael de Estrada on 11 Nov 2013, 12:23 p.m.,
in response to message #1 by James Williams

Quote:
For example, pressing Apps-->Geometry makes the calculator reboot every time.

You may have corrupted the flash drive, which will require that it be re-formatted to recover the OS. Before you do that, back up your calculator to your PC using the connectivity kit. Turn off the calculator and hold down C F O + On to reboot into the calculator utilities, select FLS utility and then format flash drive. After completion, push reset button to restart calculator normally.

            
Re: HP Prime: Integrate Won't Integrate
Message #8 Posted by James Williams on 13 Nov 2013, 1:54 p.m.,
in response to message #7 by Michael de Estrada

Michael, by the time I could connect my Prime to the connectivity kit to reflash it, it had gone completely dead. It was rebooting on most button presses just before that. It was fully charged to 100%, so it's not the battery. The connectivity kit doesn't list any calculators under the calculator tab. That's because the calculator won't turn on, right?

I've tried CFO, a factory reset, On+Symb, On for 10 seconds, the reset button on the back, and removing the battery. Is there anything else to try before I call HP to get a new one?

Thank you very much for all your helpful tips.

                  
Re: HP Prime: Integrate Won't Integrate
Message #9 Posted by Tim Wessman on 13 Nov 2013, 3:04 p.m.,
in response to message #8 by James Williams

Nope. Please call. Definitely something wrong there.

Edited: 13 Nov 2013, 3:05 p.m.

                  
Re: HP Prime: Integrate Won't Integrate
Message #10 Posted by Michael de Estrada on 13 Nov 2013, 3:07 p.m.,
in response to message #8 by James Williams

Did you press and hold C F O and then press and release On, or just C F O ? If it's not rebooting into the basic utilities menu for the calculator, then it's probably kaput, since this is completely independent of the HP OS. It's similar to the BIOS CMOS utility on your PC, which should reside in its own non-volatile ROM.

                        
Re: HP Prime: Integrate Won't Integrate
Message #11 Posted by Brock on 15 Nov 2013, 12:37 p.m.,
in response to message #10 by Michael de Estrada

I have been trying to do the examples in the manual, which work on the emulator, but not on my calculator. For example, when I perform int(1/x) I get inf on the calculator, but ln(abs(x)) on the emulator. Also, when I try to find roots, all I get is [[]] on the calculator. I have tried these remedies you have prescribed but to no avail. What do you recommend?

Thank you.

                              
Re: HP Prime: Integrate Won't Integrate
Message #12 Posted by Brock on 15 Nov 2013, 12:44 p.m.,
in response to message #11 by Brock

Also, it shows that x is zero no matter what I do to change that.

                                    
Re: HP Prime: Integrate Won't Integrate
Message #13 Posted by Brock on 15 Nov 2013, 12:54 p.m.,
in response to message #12 by Brock

Another example:

diff(x^2) is 2x int(x^2) is 0 which is incorrect.

What could be messing up the integration like this? Root finder behaves similarly.

Thanks, again.

                              
Re: HP Prime: Integrate Won't Integrate
Message #14 Posted by CR Haeger on 15 Nov 2013, 1:09 p.m.,
in response to message #11 by Brock

Quote:
I have been trying to do the examples in the manual, which work on the emulator, but not on my calculator. For example, when I perform int(1/x) I get inf on the calculator, but ln(abs(x)) on the emulator. Also, when I try to find roots, all I get is [[]] on the calculator. I have tried these remedies you have prescribed but to no avail. What do you recommend?

Thank you.


Hello - I've screwed this up in past too.

I think you may have stored 0 into x while in CAS mode (a CAS variable). If so, you'll see it in Vars/CAS. To delete this CAS variable, you can type purge(x) ENTER or use Toolbox/Catalog/Purge() - both are a pain but will delete only the x value. If you Shift/ESC (Clear) while in CAS this will erase ALL the CAS variables. I ended up setting a USER key for purge()...

After that, you may want to ensure you have CAS set to Exact using Shift/CAS (Settings). Otherwise you may get "bad argument value" if you plan to look for symbolic (exact) output.

Now, int(1/x) should give you LN(|x|). diff(x^2) should give 2*x and int(x^2) should give 1/3 * x^3

Roots or zeros()should also work.

Best, Carl

Edited: 15 Nov 2013, 1:13 p.m.

                                    
Re: HP Prime: Integrate Won't Integrate
Message #15 Posted by Brock on 15 Nov 2013, 1:20 p.m.,
in response to message #14 by CR Haeger

Thank you very much for your help.

However, it still didn't fix my problem.

No matter what I still get a user variable of x...and it equals zero for some reason.

Is there no way to restore default settings, etc. on HP Prime?

Seems that would fix it?

Thank you, again, I appreciate your help.

Brock

                                          
Re: HP Prime: Integrate Won't Integrate
Message #16 Posted by CR Haeger on 15 Nov 2013, 1:25 p.m.,
in response to message #15 by Brock

Hmm,

BEFORE resetting (with pin) or other,

If you saved a CAS variable x, I would enter: Purge(x) then hit Enter key. This will delete a CAS variable x

This will then display either 0 or "No such variable x". Double check by looking at Vars / CAS and x should not be listed.

----------

If you saved a USER variable x (which may be what happened), then go to Vars/User and highlight (but dont click on) the x if its there. Hit the Del (backspace) key which will delete the x from the USER variables list.

Good luck.

Edited: 15 Nov 2013, 1:31 p.m.

                                                
Re: HP Prime: Integrate Won't Integrate
Message #17 Posted by Brock on 15 Nov 2013, 1:32 p.m.,
in response to message #16 by CR Haeger

Yes! That worked! Thank you so very much.

I am very rookie to the Prime, though I am an avid HP lover (makes my 4th HP calculator -- 12c, 15c limited edition, 35s, prime).

Thanks, again.

Have a good day.

Brock

                                                      
Re: HP Prime: Integrate Won't Integrate
Message #18 Posted by CR Haeger on 15 Nov 2013, 1:41 p.m.,
in response to message #17 by Brock

No problem - I only have a few more weeks on the PRIME than you, so I'm no expert.

After you get comfortable with some of the CAS functions: int(), diff(), solve(), zeros etc() then you might find the Spreadsheet App USING these functions even more interesting.

Being able to enter a expression in a cell and having other cells symbolically and/or numerically operate on the expression in their cells is pretty cool.

Enjoy.


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