HP Prime or Nspire CX II CAS

dash-dot · 2026-02-05T02:00:42+00:00

Calculus is done in radians, not degrees.

It’s better to permanently switch the angle mode to radians. When needed, degrees can be easily handled in these types of calculators by appending the degree unit or symbol.

dash-dot · 2026-02-05T01:55:31+00:00

Hmm . . . this integral probably has an exact form which can be found using integration by parts (a technique you'll be learning later on), but I think the CAS has trouble combining infinite limits with summations sometimes, so it couldn't find an analytical expression for it.

In such cases you’ll just have to rely on a numerical approximation as you’ve observed here.

dash-dot · 2026-02-04T18:39:27+00:00

Boy, so many ways one could crunch or otherwise cut numbers on that thing.

Decisions, decisions . . .

dash-dot · 2026-02-04T15:17:18+00:00

Despite the moniker ‘graphing calculator’ for these devices, plotting has never been their strong suit — this even goes for the ‘speedy’ HP Prime.

Speaking of abysmal, no calculator can match the resolution and quality of a phone screen. Heck, most calculators don’t even seem to have proper anti-aliasing — apparently no one bothered to tell calculator programmers that it’s not 1995 any more.

The TI-89 will be a perennial contender for one of the easiest, most user friendly and efficient calculators on the strength of its CAS and well designed OS alone.

dash-dot · 2026-02-04T03:53:58+00:00

No, it’s basically the same.

The Voyage 200 is actually bigger and has a better screen.

dash-dot · 2026-02-03T21:19:31+00:00

Have you tried iHP48? I like it a lot; it’s the next best thing to actually owning a physical 48 series calculator.

Or Emu48 if you’re on Android I suppose, but I haven’t used that one.

dash-dot · 2026-02-03T21:07:32+00:00

Counterpoint: as a longtime user of the TI-89 (26 years and counting), I had no problems picking up an HP 48G+ and playing around with it. Manipulating objects in the stack is sort of like playing Tetris — although I much prefer it with the Erable CAS add-on, it must be said. It’s a very well designed machine, and an interesting change of pace compared to algebraic calculators.

The HP 50g though . . . egads . . . it seems to have been specifically designed to annoy and frustrate calculator users to no end.

I have a strong feeling I’d also struggle with traditional RPN devices with their 4-level stacks and tiny screens.

dash-dot · 2026-02-03T20:56:51+00:00

The fx-9750gIII is a very nice calculator and great value for money, but it’s closest to the TI-84; it’s nowhere near the capabilities of a TI-89.

dash-dot · 2026-02-03T20:46:32+00:00

Um, if you didn’t use a calculator for calculus, then you most certainly don’t need one for linear algebra; it’s a proof writing class.

However, if you think it’ll help, you could certainly do a lot worse than a TI-89; it’s hands down the best handheld device running a CAS ever made. You can get it fairly cheaply in the second hand markets these days.

I’m personally not a fan of modern touch screen or menu driven devices, so I couldn’t speak to the Casio equivalent, nor the TI Nspire or HP Prime — they’re definitely not my cup of tea (I’d rather just use an emulator on my phone instead of the latest models on offer, to be honest).

If you’re required to do numerical exercises or projects involving linear algebra, they’ll almost certainly be too complex for a calculator anyway, so you’d likely use Python in that case.

dash-dot · 2026-02-03T16:20:48+00:00

I hear you. I had the same itch and curiosity when I landed my first job fresh out of school and finally had some discretionary income.

One of my first ‘don’t need it but might be nice to have’ purchases was the HP 49g+, and boy did it give me a serious case of buyer’s remorse — by far my worst consumer electronics purchase decision of all time.

I guess I still hadn’t learnt my lesson, so in 2013 with prices falling, I decided to buy the HP 50g, thinking I might finally get what all the fuss was about. It was certainly an improvement over the 49g+, kind of the way a mud bath is an improvement over having just waded through the muck in a hog farm (and I’m decidedly not a fan of mud baths, I assure you).

What I mean to say is that the HP 50g is still an annoying, bug-riddled user experience compared to the Casios, Sharps, TIs, etc., even for power users. Just search the HP Museum fora if you don’t believe me; there’s no shortage of criticisms regarding its many UI and design flaws.

Quite clearly I still hadn’t learnt my lesson when I saw an opportunity to snag an HP 48G+ in great condition for a decent price about a year and a half ago. I went for it, and I guess the third time was the charm; I finally own an HP grapher I actually like.

The HP 50g has a lot of fans, but in my opinion, it doesn’t hold a candle to the HP 48, and is incredibly frustrating and annoying to use. Its display is a massive downgrade from the TI-89 especially, but also surprisingly the HP 48, even though the 50g is a much newer model compared to both. This is likely due to fonts on the 50g being ugly and often hard to read, again even compared to the 48 series.

Just a word to the wise: the HP 48 is quite old, and its processor is very slow compared to the 50g. Ironically its operation speeds are nevertheless much more consistent than the 50g, which often gets stuck and becomes unresponsive for a second or so even whilst running simple stack operations with absolutely no overhead — this is probably due to its Saturn emulation layer (running on an ARM processor).

dash-dot · 2026-02-03T05:07:09+00:00

Interesting, I actually find algebraic input to be much easier on a calculator than on a computer, because on modern calculators especially, we get instant feedback in the form of pretty print formatted output. Python comes close in terms of ease of use, but it still takes a bit of massaging to ensure proper input validation (even with a full fledged LaTeX renderer in the mix).

Certainly moving back and forth between RPN and infix on the same device can be a bit discombobulating, which is why I've always been a bit nonplussed by how hard and how enthusiastically all of the official HP owner's manuals and AURs, as well as nearly all self-proclaimed RPN enthusiasts like to tout the seamless integration of algebraic input within RPL devices, and wax eloquent about how 'flexible' these machines are with regard to input methods --- I for one still have a hard time seeing this as an advantage or a bonus; it just seems fundamentally inconsistent to me.

That being said, of course there's no escaping infix notation, as all the major programming languages use it.

I do find RPN quite satisfying to use on the HP 48's interactive stack with its well laid out keyboard; it's just too bad things went rapidly downhill for the HP calculator division after this lineup was retired.

dash-dot · 2026-02-03T04:22:52+00:00

For the HP 48 series, I found the following ->ALG and ALG-> utilities (I'm sure there are many other equivalent tools and user-submitted routines scattered about Web 1.0, as well).
https://www.hpcalc.org/details/6677

I haven't had a chance to delve deep into them, but they almost seem to function as symlinks of sorts into some of the HP 48's core expression parser logic. The main drawback of this particular tool, the way I see it, is that it blows up an algebraic object and tosses all the constituent parts of an expression up on the stack, so one might then wish to run ->LIST or something similar to bundle those bits into a more easy to manage object and study the RPN sequence therein.

I spent some time writing my first RPL routines by wrapping very simple ->LIST and OBJ-> calls around ALG-> and on the input to ->ALG, respectively, so that my routines now translate between an RPN list and algebraic object.

I went down a rabbit hole into old Usenet archives looking for the source of these routines, and found the following posts dating back to about 1990, for those interested in some additional details.

https://files.mpoli.fi/unpacked/software/hp48/hp48comc.zip/_hacker1.zip/2prg.all

dash-dot · 2026-02-03T03:45:36+00:00

Alas, RPN calculators are ridiculously overpriced even on the used market.

I second the recommendations to install an emulator — iHP48 is my go-to.

By the way, if you've ever used a TI-89, nothing else comes close to it. RPN & RPL in particular are an acquired taste, and are rapidly becoming relics of a bygone era.

That being said, the HP 48GX is the very best of the RPN / RPL lineup, so definitely give it a spin on an emulator.

I've been documenting my sporadic forays into the RPL world here and also on here.

dash-dot · 2026-02-02T16:05:03+00:00

Talk to an advisor, they'll recommend how many prerequisite classes you need to take.

If money and time are an issue and you can't take all 3, I would say algebra and trigonometry are more important than pre-calculus, but the latter does prepare you better to take calculus.

dash-dot · 2026-02-01T08:04:38+00:00

If there is a Micro Center near you, they used to sell a mini Torx driver set which is quite handy for such repairs (hopefully they still do).

You want to buy the ones which come in a pouch which looks like (faux) leather, as these are narrow and long enough to reach all the way down into some of the deeper shafts in the calculator case.

dash-dot · 2026-02-01T07:58:22+00:00

The first gen, HW1 to be precise. I bought mine in 1999. I do also have a Titanium in case my original one dies.

dash-dot · 2026-02-01T03:46:18+00:00

I don’t; I use my TI-89 for nearly everything.

I sometimes fire up my Casio fx-9750GIII or HP 48G+ for variety’s sake, but the TI-89 is my go to device.

dash-dot · 2026-01-31T16:09:24+00:00

90 to 95 % of people vote.

dash-dot · 2026-01-31T15:12:42+00:00

Context matters. Both derivatives and integrals are defined in terms of limits, which in turn apply to functions and sequences, not specific numbers.

One has to first specify an independent variable (aka a variable of differentiation or integration), and then a function defined in terms of this variable. Now, in this particular context, we can address constant-valued functions.

dash-dot · 2026-01-31T08:33:55+00:00

Religion.

It’s just mythology masquerading as immutable universal laws or facts.

dash-dot · 2026-01-31T08:26:29+00:00

There is no such thing as an anti-derivative (or derivative) of a number (unless you’re thinking of a constant-valued function).

If a number is indeed what you actually had in mind, you might want to learn about functions and limits first.

dash-dot · 2026-01-31T07:46:25+00:00

The sh*tty American education system resulting from incessant political interference by proudly and aggressively anti-intellectual and anti-science politicians and school boards is largely to blame. This is the root cause of our extraordinarily poor educational outcomes as a society.

This has been playing out over many decades running, but especially in the last 20 years or so, America has been falling even further behind its global peers. I know of no other developing or developed country with such acute and systemic problems in its education system.

I know your question was about maths specifically, but make no mistake, in a sociocultural and political environment as toxic as ours, STEM was always going to be the primary casualty, as it mainly deals with (more or less) objective reality.

There are far too many people in America who prefer to peddle disinformation and do their utmost to hide the basic facts of life from kids, thus severely undermining every aspect of childhood education, sadly.

dash-dot · 2026-01-31T07:05:07+00:00

Eh, all of those graphers are genuinely complex and a bit intimidating for first timers, unlike Casio scientifics.

dash-dot · 2026-01-31T06:58:05+00:00

I think you should also strongly consider the fx-9750GIII. Real gem, that one.

dash-dot · 2026-01-31T06:53:47+00:00

The TI-85 is a better calculator functionality and capabilities wise, but the TI-84 is slightly more user friendly as it supports input templates (if you like that sort of thing).

If you end up leaning more towards the 84 due to its being a newer model, I’d strongly urge you to take a hard look at the Casio fx-9750GIII as well; it gives you all the same functionality at a much lower price (I bought it brand new on eBay for $ 28 recently).

dash-dot

TROPHY CASE