Solving Definite Integral with unknown upper bound with the hp Prime solver (v2)

[@danrosenthal407]

I typed in the integral without enclosing it with parentheses. Then, I hit Enter. Then, I edited the expression and typed "=5". Solve worked perfectly.

[@scottcollins7513]

Ideally, it should not require those sorts of gymnastics, but thanks for sharing an alternative approach, Dan.

[@danrosenthal407]

@@scottcollins7513 Definitely a bug! I even typed it in using int(expr, x, 0, A)=5 which has the parentheses. It still gave the syntax error. In which case the template version has no chance. Thanks!

[@commtechengineer612]

The HP Prime is an incredible machine, I still need to pick one up!

[@scottcollins7513]

It has a ton of power, but for the basic things I do, I prefer the accessibility and ease of programming of the DM42.

[@funnycats4962]

There's another way which worked on mine: just needed to put a space before the equals sign (so instead of "...dX=5", do "...dX =5"). This is how I intuitively typed it anyway the first time and so I didn't see the error. At first I thought my calc's OS was newer and I didn't have the bug. But then I noticed in Symbolic View, HP's own code removed the space when displaying the entire equation string in the "E1" textbox (going back into edit mode made the space reappear, though). That gave me a clue into thinking it might not be "()" that fixed your problem, but any character that buffers the end of the equation with the left of the equals sign.

[@scottcollins7513]

Interesting that the space does the trick, too. Either way, the Prime has a picky parser (I think that is the term). Thanks for sharing the comment.

[@odarge]

workaround nbr N ;-) For this equation to integrate, without fussing with parenthesis, this works well : -5+ => solve works

[@cRyS112]

could you please help? if i write in solver dx/dy = f(x), can this calculator separate the variables and after that integrate if i define the upper and lower limits? if not, is there any way to avoid doing the variable separation by hand?

[@scottcollins7513]

I think you are over my head on this question. I've done this sort of thing long ago, but never using technology. If you are allowed to use tech, then why not start with something really powerful -- how about giving Wolfram Alpha a try and see if it can solve the type of problem you are talking about?

[@jacoboespinosaperez01]

hey I am struggling trying to do upperbounds. Please help.

[@scottcollins7513]

Can you provide more details? Are you trying to do what I am showing in the video or something else?

[@laszlotompa624]

Not bug ! Just feature... After entering integrate go to the end of the line with the right arrow (space will be there) then enter "=5" and then go back to enter integrate parameters. Works fine. HP Prime G1

[@scottcollins7513]

You have solved the riddle. The sphinx of hp will be impressed. Thanks for the info, Laszlo.

[@zwan1886]

Maybe someone can help me... I'm trying to do a really simple integral but the HP prime keeps giving me an error. The integral is from 0 to 1 of (X + 1) Y^ (X+1) dY where X > -1

[@scottcollins7513]

I don't understand the integral you've been given. That Y in the middle and the dY are definitely throwing me off. Any chance you can write/photograph/typeset the problem and provide a link to it?

[@zwan1886]

@@scottcollins7513 Here is the plain text and solution from wolfram alpha: integral_0^1 (θ + 1) y^(θ + 1) dy = (θ + 1)/(θ + 2) It's something I can do by hand in about a second but HP prime says it is undefined. Thank you.

[@scottcollins7513]

@@zwan1886 Thanks for posting the wolfram alpha text (good thinking to do it that way!). I understand the question now. But, I also understand w/ the Prime is struggling, since it is not as straightforward, given the two variables (albeit, the theta is treated as a constant). I noticed that in your original question you show the X and Y as capitalized -- typically in CAS mode, those would be lowercase variables. Doubt that is the issue, but thought I would at least bring it up. The other thought is that maybe you need to either clear all values from x or store some arbitrary value in x to get it to work. Other than these ideas, I do not have any suggestions.

[@cosmokayat]

On my G2 I enter the equation without parenthesis but with a space between dX and =5. Works fine. Gives Bad Guess message with dX=5 all together. In the equation list it shows no space! But if you 'Edit' is shows the space. Works on my phone app this way too.

[@scottcollins7513]

I tried the same (adding a space between dX and =5) on my old Prime without any updates and it still gives the "bad guesses". hp have fixed the issue from what I understand, but with older models like mine that are running the old firmware you will need the parentheses. Thanks for the feedback, cosmokayat!

[@AnotherBuddha]

Thanks for the Video. Not sure if my Hp Prime G2 with the latest software still does that. I will check later, and hopefully let you know

[@scottcollins7513]

You are welcome. If you do have a chance to try it out on your calculator, let me/us know what you discover.

[@AnotherBuddha]

I tried it. They corrected it. No problems doing it on newest software and hardware.@@scottcollins7513

[@scottcollins7513]

@@AnotherBuddha GOOD INFORMATION. Thanks for checking it and letting me/us know. Glad to hear that hp corrected the bug.

[@AnotherBuddha]

@@scottcollins7513 I am thinking of doing KZbin videos. Teaching people how to utilize the power of the Hp prime. 2300+ functions. 700 page manual. Its a lot to digest.

[@scottcollins7513]

@@AnotherBuddha It is a very capable calculator (much more power than I typically need), but it is not particularly intuitive (to me). You could start out with, say, 5-10 videos on functions you find useful, but that are (1) not easily figured out and (2) that don't already have easily-searched-for videos.

[@abather11]

What is the closest to perfect calculator?

[@scottcollins7513]

My first thought is that this is like asking “What is the closest to perfect tool?” It depends on the job to be done. Engineering? High school math? General use? My personal favorite is the SwissMicros DM42, but it is very pricey. I think it is the closest to perfect for me. I think the CASIO fx-115ES PLUS is a fantastic calculator for around $20 and is my favorite in this price range (the CASIO fx-991EX and the TI-36X Pro are also great choices). Great for high school. Much better than the TI-84 that is far too expensive for what you get. I think for engineers, the hp 48GX was amazing. I used an hp 28S when I was in engineering school in the late 80s -- it was a beautiful machine.

[@odarge]

@@scottcollins7513 hi Scott. Did you try the 50g ? I like the 48G as well. For quick and easy programming I like DM42 as well. It’s a refreshing RPN experience should I say 😉

[@scottcollins7513]

@@odarge I have a 28S, 48GX and DM42. DM42 is my favorite calculator currently. I’ve never used a 49 or 50 calculator. RPN is generally great.

[@scottcollins7513]

@@no_fb hp 28 is my favorite hp keyboard. hp 48 is also great, but still second to the hp 28. The DM42 is definitely not nearly as good as those classics. In fact, I think the hp Prime keyboard has a better feel than the DM42. That said, the DM42 keyboard after the update (DM42's purchased on or after September 25, 2020 per SwissMicros' tech support) is good -- just not hp-superb.

[@odarge]

@@no_fb Like Scott says, current DM42 has a good keyboard, not as sweet as the Prime one. That said, DM42 is a fantastic tool with a great screen. His pads could have been larger for a better stability. HP28S gave me the better memories tough, I was young and engineer student too ! :D :D

[@alpham9877]

don't you have a ti89

[@scottcollins7513]

I did at one point, but not any more. I have the hp 48GX.

[@bolleke702]

TI is for dummies, HP-48GX is for engineers :D It is just... well.. very well designed and of a very high quality. Everything works the same way, whether you have numbers or matrices or anything on the stack. It uses operator overloading. You don't have to go through endless menus, you have directories, user keyboard, custom menu's and so on.. Just work with an HP, compare with your TI89 and then talk.. Oh, and the HP-Prime is also a toy for me. Not so well designed. Also the keyboard layout and color-scheme are not good. The quality of the product and keys however is very good, much better then the other brands.

[@fernandoj.sulsonaanziani6195]

Great! Thak you.

[@scottcollins7513]

Glad you liked it -- really appreciate the encouraging comment, Fernando. Take care.

[@calypsocostelo2482]

The HP Prime Virtual Calculator Emulator (64-bit) for Windows is 100% FREE, fully unlocked and unlimited use. Search for this key words to get a link for the exe file. HP_Prime_Virtual_Calculator_x64_2023_04_13 😀