Hyperbolic functions post 35

[Matt Agajanian]

Hi all.

The SR-50 was introduced in January '74. With it came hyperbolic functions. So, why did HP calcs lack hyperbolic functions until the 32E?

Thanks

[Maximilian Hohmann]

Hello!

(09-08-2022 01:18 AM)Matt Agajanian Wrote:  So, why did HP calcs lack hyperbolic functions until the 32E?

Of course we can only guess, but maybe HP thought that programmability is more useful than a large set of hardwired functions (similar to the RISC architecture in computers which was, by chance?, also introduced in 1974). In the same year as Ti lauched its first hyperbolic calculator HP introduced the HP-65 and several software packs, one of which (Math Pac 1) does add hyperbolic functions to the calculator.

Regards
Max

[RMollov]

why sqrt 1 equals 1?

[EdS2]

(09-09-2022 06:27 AM)RMollov Wrote:  why sqrt 1 equals 1?

I don't understand what you're trying to say with this comment. Could you perhaps be more clear?

[Thomas Klemm]

(09-23-2021 06:06 AM)RMollov Wrote:  if you ignore some stupid repeated 'questions' Matt Agajanian style

[EdS2]

But is this forum a good place for petty hostility and mocking? I hope not.

[Dave Hicks]

Someone (I wish I could remember who) at HP told me that when people would ask for hyperbolics, they (can’t remember if it was this person specifically or HP in general) would ask what the customer used hyperbolics for, and they rarely received an answer. So, they just thought customers were just checking off a list and they concentrated on things they thought customers actually needed. (As I recall, TI advertisements of the time were often based on the comparisons of lists and possibly the cause of many of these questions.)

I think this is a perfectly legitimate and interesting question. If a question doesn’t happen to be your cup of tea, I would encourage you to just ignore it and move along to the next one. Please don’t mock questions or questioners.

[Paul Dale]

I'm inclined to agree with David here. It's a checklist item and comparisons are done with checklists rather than what is actually necessary.

Our new dishwasher is internet connected. It's one feature is that it can be started via an app. Of course, you need to have stacked it, put in the detergent, closed the door and then forgotten to press start. It's a feature without a point. I suspect it also reports home about usage etc but that's of little benefit for me.

An older example is VCRs which went through a long series of feature oneupmanship where ever more capabilities were crammed in but people still mostly use play, pause and sometimes record. Likewise MP3 players -- at least until Apple stripped it back to the essentials.

[Matt Agajanian]

(09-09-2022 09:42 AM)EdS2 Wrote:  But is this forum a good place for petty hostility and mocking? I hope not.

Thank you. Thanks for coming to my defence. This is a forum for ALL of us, no matter what questions we have or our skill level. I’d like to feel welcomed here.

[Steve Simpkin]

Matt, the more I research this the more interesting I find it. Just looking at LED models, I think the HP-32E was the only model that had hyperbolic functions built-in. It is even lacking as a standard feature in the HP-41C. The scientific Voyager, Pioneer, HP-48/49/50 and future models seem to all have it.

Regarding TI LED models, as you note they did include hyperbolics on their first scientific model the SR-50. They were also on the SR-50A, SR-51, SR-51A and short lived TI-55. Hyperbolics may have been on other TI LED models but I don't think so. TI made a lot of LED and LCD scientific calculator models.

http://datamath.org/Album_Sci.htm

[EdS2]

The only thought I have about the usefulness of hyperbolic functions is something vague about the catenary function - but hanging cables or chains across gaps is a very real-world thing to do.

A bit of web-searching turns up this

Quote:They are very useful in relativistic physics. Cosh and Sinh are the Lorentzian geometry analogs of Cos and Sin. Just like rotations preserve distances in the plane and can be written in terms of "cos" and "sin", there are transformations in Lorentzian geometry which preserve "proper time", the analog of distance, and are written in terms of "cosh" and "sinh".

and

Quote:I'd say they are most important in differential equations. The very simple equation y'' = ky shows up in many many places, and the solutions are sinh and cosh when k is positive.

But as a kid with an interest in calculators, I remember noticing the Casio machines had these extra functions, compared to mine.

[Maximilian Hohmann]

Hello!

(09-10-2022 07:35 AM)EdS2 Wrote:  ...I'd say they are most important in differential equations. ...

As far as I am concerned I would agree. The only time I have ever come across hyperbolic functions was in connection with differential equations. Back at university. But, as already discussed in an earlier thread, at university the numeric result of an excercise was of secondary interest. You would already get full points for writing something like y = e^−x/6(c1 cosh(x2) +c2 sinh(x2))

The Ti-59 I had back then would not have been able to compute hyperbolic functions unsless one either programmed them oneself (as I certainly did even if I don't remember now...) or bought the "Math Utilities" module.

Regards
Max

NB and off topic, regarding Paul Dales reply: On of my super-hardened-iron-clad rules is to never ever let a dishwasher or washing machine run unattended when nobody is at home. I know many cases among family and friends where a malfuntioning washing machine has caused considerable damage by flooding the appartment. I certainly wouldn't want to drown my calculator collection in dirty dishwasher waste water... Therefore the first thing I would disable in such a machine is the remote operation!

[Steve Simpkin]

I'm pretty sure HP did an extensive focus study (sparing no expense) and determined that the HYP key was not important to most people:j
   

[ijabbott]

(09-10-2022 12:09 AM)Paul Dale Wrote:  Our new dishwasher is internet connected. It's one feature is that it can be started via an app. Of course, you need to have stacked it, put in the detergent, closed the door and then forgotten to press start. It's a feature without a point. I suspect it also reports home about usage etc but that's of little benefit for me.

Maybe it will order the most expensive dishwasher detergent pods manufactured by its manufacturer's chosen partner company for you.

[Thomas Klemm]

(09-10-2022 07:35 AM)EdS2 Wrote:  The only thought I have about the usefulness of hyperbolic functions is something vague about the catenary function

They can also be used to solve quadratic or cubic equations.

[Paul Dale]

(09-10-2022 09:55 AM)Maximilian Hohmann Wrote:  Therefore the first thing I would disable in such a machine is the remote operation!

Agreed. Fortunately, the option needs to be enabled by connecting the device to my local network. Which is never going to happen.


Pauli

[EdS2]

(09-11-2022 09:57 PM)Thomas Klemm Wrote:  

(09-10-2022 07:35 AM)EdS2 Wrote:  The only thought I have about the usefulness of hyperbolic functions is something vague about the catenary function

They can also be used to solve quadratic or cubic equations.

That's nice - thanks for the link!

[KeithB]

I think the HP71 (and probably HP41) had a good solution in putting them in the accessory ROM's.

[n1msr]

Interesting discussion.

I wondered why, when I bought the HP-67 in 1978, it didn't have hyperbolic functions, which my 1976 bought SR-50A did. I was at school until 1980, and the main reason I did Further Maths A-level (UK exam for 18 year-olds) was because it covered hyperbolics, albeit to a basic level. When I was 14 (in 1976) I had the SR-50A and asked my maths teacher what hyperbolic functions were and would we be doing them in class. He said - "only if you do Further Maths at A-level". That decision was made there and then, for me. The SR-50A manual gave the catenary use case for hyperbolic functions, as mentioned in this thread as a common use case.

It is good practice sometimes, as has been pointed out in this thread, that leaving a symbolic expression is often better and more meaningful than a pure numerical answer. However, being able to obtain a numeric value quickly is sometimes useful and even interesting. It also helps when you want to draw a graph.

Anyway, I got an HP-15C in 1982 and rather neglected the HP-67. Not because of hyperbolic functions, but because the 15C batteries lasted "forever" and the matrix plus complex number handling was useful in electrical engineering.

As of December 2023, the HP-67 is back on my desk with Tony Nixon's enhanced CPU board. Fantastic!

Sorry for such a long story. We've all got them :-)

[John Garza (3665)]

The 9100 had hyperbolics in 1968.
Then, for some reason, they were dropped on later machines.

-J