TI-89 Titanium Graphing Calculator with Computer Algebra System (CAS) by Texas Instruments

Placeholder: Thanks Amazon for helping me save 50% by getting a refurbished calculator in excellent condition! I feel good both because of the price and because the electronics gets reused.

United States on Oct 30, 2023

John Moran: College courses are quite difficult but this calculator is making work faster and easier!

United States on Sep 21, 2023

DIYEngineer: Had one of these from high school all the way through engineering school and beyond. It did become a bit much to use in the field due to its size but it never failed me. So it's now that it's time for my son to start needed a graphing calculator for his high school calculus I knew exactly which one to buy.

United States on Aug 29, 2023

Evan: This is surely a niche product, but if you really need one, it comes as advertised: brand new Ti89 in box with batteries and all

Canada on Jan 12, 2022

GaryA: I bought the TI-89 Titanium to be compatible with a fellow engineer--it is great to be able to share code and math solutions for the same model of calculator. This is a switch for me, since I have always been a Hewlett-Packard fan. I have at least one of almost every model of HP graphing calculator, and many other models, going all the way back to 1972 and the HP 35. It never occurred to me that the TI-89 series could actually be competitive with HP. Well, it is! This calculator has some very nice features, and a few features that the similarly capable HP 49G does not. I'll leave it to the buyer to explore the manuals and figure some of that out for themselves. But I will definitely note that the Home screen edit/command line has superior behavior in several ways to the HP 49G. One of those is the retention of the last problem, equation or expression entered by the user. That means you can simply solve the first problem, then move the cursor around in the problem, replace a variable, change a sign, or make any other edit needed to evaluate the problem in different ways, without having to copy the equation/expression from the history (as you would have to do with the HP...

United States on Aug 24, 2020

Amrit: Best product ever, Except that the batteries died after a month of usage. I am using eveready alkaline now and lasts more than a year under heavy usage. Also storing self created programs is not useful as the calculator resets some times without prior notice causing the user programs and past calculations to get erased. Does 3-D graphing very well though in that small lcd screen. Using the later colour models in not useful for me as their resolution is not any where near that of the modern phones. And I wouldn’t want to remember another device to hook up every three days to the power outlet. Besides the device will be useless once the rechargeable battery dies. This one though can run a lifetime if maintained properly as it uses disposable akaline batteries. And awesome for quick and dirty calculations when you don’t want a full fledged laptop.

India on Dec 30, 2018

Gurveer: Everything is great about the calculator. Just the graphing is little slower than the other models of Ti calculators

Canada on Oct 30, 2018

E. G.: Sehr gutes Gerät; da ich das Vorgängermodell hatte, habe ich mich wieder für den TI-89 entschieden.
Einziger Kritikpunkt die Produktbeschreibung stimmt mit dem Lieferumfang nicht ganz überein

Lieferumfang lt Beschreibung auf amazon:
4 AAA Batterien => check
USB-Kabel für die USB-Schnittstelle => check
USB-Kabel für die Verbindung zwischen TI-Rechner und Computer => check
Handbuch => leider nein
Produkt CD der verfügbaren Software einschließlich der frei erhältlichen Applikationen und der Handbücher als PDF => check

Ein physisches Handbuch aus Papier war leider nicht dabei. Desweiteren täuscht das Titelbild (was ich allerdings nicht negativ werte), da das Gerät selbst in einem Karton statt in einer Plastikverpackung kam.

Germany on Jan 05, 2018

TheLevia: Ho ordinato questo prodotto dal venditore ConsumerCablesUSA il giorno 3 giugno 2017.
Il prodotto (una Ti 89 Titanium) è arrivato il giorno 27 giugno, adeguatamente imballato, è stato spedito dall'america.
Secondo il tracking il pacco è stato spedito utilizzando DHL dall'america, quindi è arrivato in Italia dove è stato bloccato in dogana per circa 10-15 giorni, da li è stato spedito utilizzando la posta ordinaria ed è stato consegnato.
La descrizione diceva "usato in ottime condizioni" ed effettivamente è proprio così, la calcolatrice è immacolata, presenta segni di usura quasi impercettibili, non presenta graffi sulla cover e sono presenti ancora i gommini sulla custodia/calcolatrice, è pulitissima ed i tasti non sono sbiaditi/usurati, il display è perfetto ed è difficile distinguerla da un prodotto nuovo.
è arrivata solamente la calcolatrice, senza batterie (servono 4 ministilo per farla funzionare), senza cavo (che comunque non è una gran perdita visto che basta un qualunque cavo miniusb) come chiaramente indicato quando ho fatto l'ordine.
Per quanto riguarda il prezzo, la cosa che mi ha fatto storcere il naso è che al momento dell'ordine ho...

Italy on Jul 01, 2017

Matthew Sutton: There isn't alot I can say about this calculator which hasn't been discussed by previous reviewers. I, like the majority of them, and probably you the reader, have an 83 and got into a calculus course, or calculus-intensive course, and realized that the 83 was no longer going to cut it. Well I got the 89 from amazon and since that day the 83 began to look more and more primitive...sigh...The 89 can factor, differentiate, integrate, sum, products, binomials, solve systems and matrix operations, etc. It can also graph in 3d, polar, or differential field (what you may have seen in the promo shots). It even has the option of exact or approximate answers. A very helpful option I've found is the stored units of measurement you can use in the cases where you need to work problems in physics, engineering or even chemistry. After about two months of use I'm still learning just how much this graphic utility has to offer, but the user-interface has long since become completely intuitive for me. But the buyer should beware if they are making the transition to this right before the final--its menu style interface takes a day or so to get used to, and the manual while long isn't as...

United States on Nov 05, 2006