HP PRIME 02 - Solving an equation, programming and complex numbers.

This is a short video that explores using the 'solve' function of the CAS environment, both with real numbers and with complex numbers. The video also describes the programming a simple "two resistors in parallel" program.

[@viniciusgotosleep]

I'm starting electrical engineering, this video has absolutely sold me on the HP Prime above the others. Operating it looks so seamless compared to the others.

[@technics6215]

This is the best explanation how HP Prime can be used in electrical engineering. Thank you Sir.

[@BunkerSquirrel]

I love my Prime to death. I’ve had this thing for almost a year and it still blows me away how much it can do. Cheers!

[@rolinychupetin]

I agree. It is quite an impressive machine.

[@chef1arjunaidi]

Thanks, Professor. After keeping the Prime in cold storage for a long time, i finally learned how to create a program. You're the best, I wished you were my professor. Looking forward to learning from you again.

[@rolinychupetin]

Once you get acquainted with the CAS of the Prime, you'll neer look back. I only wished that it had existed when I was an undergraduate student. But then again, I was the transition generation from slide rules to the HP-35, the first one, the original one. I still remember the thrill of finding a sine, or a cosine just at the press of a key (before the 35, engineering students used booklets with tables to find logs and sines cosines and the like.)

[@nagyelraheb4165]

Thank you for your videos. I'm an engineer who has the same memories of sin, cos and log tables on our desks during an exam :) I remember the smile on my face when my first calculator gave an answer of "E" for 5 divided by zero :))@@rolinychupetin

[@henrikkliebhan4874]

Superb video, with a high density of information and the granularity to understand the idea behind the method you show. I like your approach to explain in such a "friendly advisor mode"!

[@rolinychupetin]

Glad you enjoyed it!

[@VictorNoelCoryPaz]

Thank you. Great educational videos.

[@ALAIDI]

Very nice and beautiful explanation, thank you sir

[@Cosecant18]

Awsome! Thanks!

[@marlonhermilio]

Muchas gracias señor rollini chupetin

[@rolinychupetin]

Si va a courses.ece.ubc.ca/elec202 y entra en la opcion de "FREE SOFTWARE", encontrara los listados de los programitas que uso en mis videos, como los cinco de solucion de triangulos, SSS, SSA y otros. Tambien los de manipulacion de numeros complejos. Buena suerte.

[@crocellian2972]

Great. Do more.

[@kevinclaypool6345]

Super useful thanks!

[@rolinychupetin]

Great, thanks.

[@darioeufrausinodesousa4055]

HP the best calculador.

[@rolinychupetin]

so far ... let's see what they come up with next. :)

[@vdmur7952]

Great!

[@shantk7378]

Great series of videos! How would you suggest increasing the number of paralleled resistor values in the program from just 2 values to many (R1,R2,Rn...)?

[@rolinychupetin]

Great suggestion! Here it is below. The trade off is that the input is a list of the resistances to be connected in parallel, example: RPR({3,5,2}) returns ... well, you'll see. You can make that list as long as you need to. the code is relatively straightforward too: EXPORT RPR(m) BEGIN LOCAL gtotal,n,ix; n:=size(m); FOR ix FROM 1 TO n STEP 1 DO gtotal:=gtotal+1/m(ix); END; RETURN(1/gtotal); END;

[@shantk7378]

@@rolinychupetin Thank you! This is great. I would love to see a video on some of the other programs you've written such as the Butterworth and Chebyshev filter programs! I am absolutely loving the HP Prime.

[@dionlemans6747]

Strangely i get an syntax error, can anyone explain me why? i've filled the program exactly the same in on my prime and checked it three times?

[@pm_1]

Dear Professor, Thank you for your channel. It is valuable. But I think I see a "bug" in the RR program. RETURN should not use the "()" to return value - using it, you return the complex number a real part :). I noticed that by a small mistake. I wanted to round the output to 2 digits, so I wrote RETURN(ROUND(r1*r2/(r1+r2)),2). I was surprised that the evaluation was x+2i. I made a mistake, and I realized output is a complex number. Now I have "RETURN ROUND(r1*r2/(r1+r2),2)", and it works perfectly.

[@rolinychupetin]

I waited before responding to give time for you to realize the actual source of the wrong operation of your program. Here it goes. The line that you wrote, let me copy it RETURN(ROUND(r1*r2/(r1+r2)),2) has an error indeed, but it is not the optional parentheses after RETURN, it is that you closed the ROUND( bracket too early, it should be after the ",2" so the ROUND function receives the two parameters that it expects. Do try RETURN(ROUND(r1*r2/(r1+r2),2)). I commend your willingness to explore functions in the PRIME, but I strongly advise against using ROUND in what will be an intermediate result in a longer and more complex computation. The loss of those digits may, most likely, add up to a wrong final answer in the solution using RR. I've advised my students against that in class, and I thought it fair to add the same advice here. Thanks for your contribution and enthusiasm. There used to be a course on the propagation of errors in long computations. It was part of a Physics lab in the first year. I hope that it is still taught.

[@caulist]

Boa noite professor, Queria sua opinião pessoal por gentileza sobre se compensa trocar a hp50g pela hp prime. Pois tenho a hp 48 a mais de 15 anos e ela tem uma peculiaridade que a prime não tem:2100 funcoes embutidas (nativas), o que ajuda muito pra programar a mesma.coisa que a prime não tem.pois tenho mais de 50 programas na 50g e estes programas não é compatível com a prime.grato. Claudio Bahia _ brasil

[@rolinychupetin]

Prezado Sr. Claudio, Eu mesmo, segurei meu HP-50g durante o tempo que pude. Mas o tempo não aguarda ninguém. O HP-50g ainda é uma máquina poderosa, mas o HP-PRIME é como o HP-50g em esteróides. É verdade que você terá que traduzir todos os seus programas para Pascal (o idioma nativo do HP-50g). Mas Pascal é tão amigável (foi concebido como uma língua para escrever programas fáceis de ler) que a tradução será direta e gratificante, uma ótima oportunidade para aprender o poder do HP-PRIME. No entanto, se você se sentir muito confortável com seu HP-48gx (eu também tenho um desses), e não falta nada, e você não sente como aprender uma máquina / idioma totalmente novo e recodando cinquenta programas, então mantenha o 48gx .

[@charlesschwer1792]

HP 50, piece of cake. HP Prime, I get answers but I do not know what I am doing.

[@rolinychupetin]

I love the HP-50g too, but they don't make it anymore. I used to have three HP-50gs, but my daughter put one of them in the washing machine, along with my blankets :( I also have an HP-49gx, and I used to have an HP-67, and HP-25, (my brother lost my HP-35, original package, a vintage machine), and of course my HP-41c. The HP-Prime, in my opinion, is a worthy successor to this aristocratic line of machines.

[@charlesschwer1792]

rolinychupetin You are right, I checked at Amazon, there are already gone. They are used, and no one knows what version they are selling. I have 2.15 and do not want to go back to 2.08. Times are changing.

[@anhvunguyen1989]

Dear Professor, Apologies for the late comment, I just found and purchased a HP Prime G2 for my Engineering studies, and am very grateful for your videos. For this one, however, when I tried to solve for w using the exact steps you have mentioned, instead of nice numbers, I got some very strange, long results with _y and _x. Do you know why this may be the case and how it can be changed? (FYI I have tried again with the virtual emulator, and got the same result)

[@rolinychupetin]

Try using fsolve instead of solve and let me know.

[@mattneff1262]

Professor, do you prefer the newer programming environment over the classic RPL?

[@rolinychupetin]

It grows on you very quickly.

[@gabrielaaiolfi4843]

Can i solve the last equation simply using the "i" intead of defining j?

[@rolinychupetin]

of course. I define 'j' as in common practice in electrical engineering because 'i' is (in EE) usually a current.

[@technics6215]

Do I need HP Prime calculator, or there is PC software that remembers programs and settings? I have Prime emulator for Android, but entering big equations is a bit painful on calculator keyboard

[@NickApostolakis]

There is a free program for pc p, Mac and Linux

[@andrelclucato]

I had a HP 48S, then a 48GX. Now I've just bought a HP prime. However, in the 48, at the solve app, i used to use the equations with or without units. More than that, whit any unit as desired, since compatible with the equation. Is that possible on HP Prime? I'dnt figured out how to do this. In the equation V=S.t, entering S in 'm', t in 's', I could get 'S' in mph, or kph, or ly/y, independently of others units. Is that possible in the Prime?

[@rolinychupetin]

Dear Mr. Lucato, Usually, the equations that I solve with the HP Prime imply the units. For instance, in an induction motor, the rotating magnetic field angular velocity can be given by three different formulas depending on the units: (1) n = f/p (n in revolution per second, f in hertz and p has no units); or perhaps (2) n = 60f/p (n in revolution per minute, f in hertz and p without units); or even (3) w = 2 pi f / p (w in radians per second, f in hertz and p without units). Similarly in everyithing else of electric equipment and electronics that I work with. So the equation is different depending on the units. The CAS deals with the math, not with the units. I hope that this answers your question. Regards,

[@andrelclucato]

@@rolinychupetin Yes, I understand. I think this is a disadvantage for the Prime, but I have to deal with that. Thank you!

[@alistercarmichael4990]

The firmware now (2022) has unit conversion and si representation. Some constants are also part of the OS. You could build scaling factors in as the prof suggests, use a unit type for each (quantity) variable, express the output as a unit, or use the converter as a distinct operation after calculation. I am new to this device but it looks like just about anything can be mixed together as long as we are mindful of our reference units.

[@homo192]

When I press check after writing this simple resistor program, the (physical G2) device returns a "syntax error". I'm stuck there.

[@rolinychupetin]

The syntax error sends the cursor to the "offending" bit in the code. It could be as simple as a typo in the name of a variable.

[@EstesZ7]

How do you solve a system of complex equations?

[@rolinychupetin]

Do you mean equations with complex coefficients?

[@phrack9998]

Thanks for the video, but I cannot duplicate your answers on the last part with j and Omega formula. I've tried it both in the Android app and the PC emulator. I've verified my settings to what you had in the first video and followed step by step in both videos but I can't get it to simplify to a simple answer. What I get has a _x at the beginning added to a whole bunch of different operations at solve (IM(Req)=0,w) part.

[@rolinychupetin]

I suggest that you delete variables that may have been defined in your calculator and may be replaced into the expressions that you are working with. Something like that did happen to me at some point in the past. In a future video we will explore variables in the HP-PRIME.

[@phrack9998]

rolinychupetin I did try a Purge on the variables to no avail. I'm was also a fresh install that I used to follow along with.

[@rolinychupetin]

I'll leave your question open on this board with the hope that another of the readers can comment and find the answer to this conundrum.

[@AnnaVahtera]

On the off-chance someone reads this so far after the video was released: WHY do you have to remember to add the multiplication sign? Can't the HP Prime understand "2x"? Do you always have to specify the multiplication sign, even if you don't in, like, any other brand calculator, ever?

[@rolinychupetin]

You can write 2x, and the Prime will understand that you mean 2*x, but if you want to type x2, then you must include the x*2.

[@AnnaVahtera]

@@rolinychupetin Thank you!