Should I replace my TI-89 Swiss Army Knife on the table with the HP Prime?

[Nigel (UK)]

(07-25-2022 07:19 AM)Tom Flatterhand Wrote:  I sporadically observe the development of the HP Prime and have read some of the tests that appeared in the beginning. There were also written about some quirks. Now I got an HP Prime as a birthday present and would like to know how HP-41C, HP-48 and TI-89 owners rate the HP Prime?

Have initial quirks been eliminated over the years?

How good is the CAS compared to the Derive built into the TI-89?

How have you come to terms with the three-part nature (home mode, CAS mode, apps)?

Is it true that the TI-Nspire™ CX CAS and the HP Prime have the same CAS (Giac/Xcas)?

Maybe someone of you knows about the mentioned calculators and may answer me? i would be very happy.

I used to love my TI-89. I would still love it, if my eyesight allowed! I really like the dedicated X, Y, Z, and T keys, along with the simplicity, consistency, and reliability of the CAS. The TI documentation is also of a high standard.

However, I now prefer to use a HP Prime. It isn't just the clearer display (which is *far* better); it is that the calculator can do so much more. Graph plotting is superb (I particularly enjoy the advanced graphic app) and the touch screen is integrated well into almost everything. The CAS is certainly capable of more than the CAS on the TI-89. HP provided good basic documentation for the CAS; I have found that looking at the documentation for Xcas often reveals extra commands.

It isn't perfect. Since its introduction, bugs have been fixed but new features have been added, introducing more bugs. It isn't bug-free, and it looks now as though existing bugs may never be fixed (I hope I'm wrong about this). However, I think that most of the bugs are in commands used mainly in writing programs - I find few problems in my typical use.

There are annoyances. As an example, "Ans" (last answer) doesn't work as I would wish - if the last answer is x^2, then Ans | x=2 ought to return 4, but it returns x^2 as Ans isn't evaluated until after the substitution. (I mention this because I used to use "|" so much on the TI-89!) There are other (rare) situations in which commands appear to work, but the answer is wrong. I don't think that this ever happened with the TI-89, at least not for me.

For me, the benefits easily outweigh the problems. Try it. I think you'll enjoy it!

Nigel (UK)