Customer Reviews
it's still in good shape 
2008-03-30
it's still in good condition when it arrived but the deliver time is different from the scheduled one
Found my mistress! 
2008-03-26
From slide rulers to Ti-89's, let me tell you! Even my proessor wanted to use it! Long story short, I have never owned a graphing calculator until now. I am auditing a calculus class this summer and needed something more powerful than my Casio fx-115ES (which is sweet, BTW). My Casio can integrate, but not do diff Q's.
Well, let me start by price. My friends all suggested I bought and used a Ti-86 or even a Ti-85 unless I was going into a technical major. Surprise, surprise, I'm an engineer major. I figured if I was going to shell out over $100 on a calculator, I should choose the best available. Needless to say, everyone knew about the Ti-89. I showed it to my math professor who had the same reaction as me (think a kid on Christmas morning opening his gifts). The first thing he asked was "How much was it?" I told him I paid $140 clams and he said "Wow! How'd you get it so cheap?" It wasn't just him though. I showed my buddy in AutoCAD and he was astonished by the price as well.
Next is features. I loved the fact that it came with an instruction booklet and the batteries. It let me jump into playing with it the minute I got it. The book is about the size of a video game manual (assuming a modern-day RPG). There is a lot to read and I am still reading it. It's not too hard to figure some things out assuming you're rather savvy with electronics and have some free time on your hands. I learned to graph polynomial functions while walking to class! Italready has pre-loaded apps, but I will ask around and get some more when I finally have a chance (and some sleep), since several apps are useful for certain classes.
Next is size. I know graphing calculators are big, but wow! It doesn't fit in my pockets, that's for sure! I usually stick it in my backpack or in my cargo pockets on days when I have those kinds of pants.
Finally, utility. As I am still using it and figuring it out, it seems to do basically anything I need it to do. I am contemplating buying the Dummies' book for it since that might tell me something the instruction booklet omits, plus they often have tips within!
Overall, I would say it is a must-buy. Most of my friends (90% engineer majors) have older models and would kill for a Ti-89. It is a steal at some prices and I love the fact that even my math professor was impressed and asked me if I could bring it by his office sometime. I love calculators and this seems to be the best out there. If you don't want to break the bank, but want something good, try the aforementioned calculator (Casio) since it worked great for me!
Texas Instruments TI-89 Titanium Graphing Calculator 2008-03-08
The TI-89 Titanium Graphing calculator is the best calculator I've ever owned and used. I switched from my HP-48 GX in 2003 and never had any regrets!
The TI-89 Titanium has + and - when it is compared to the HP-48GX. For instance, the display on the TI-89 doesn't appear as big as on the HP-48 GX ( a slight minus (-)).
However, this slight inconvenience, is greatly outweighed with the overall calculator ability of the TI-89 Titanium. The calcululator can effortlessly solve integrals, triple integrals, vectors, you name it. The screen display also lets you check to see that the equation or expression you're evaluating is actually what you desire. ((BIG PLUS ++).
I highly recommend this calculator to anyone who wants the defacto "most powerful calculator in the world".
JML
It's better than we expected with excellent delivery service. 2008-03-06
I purchased the product for my son and he is thrilled with it. It's cut down his home work time and increased his accuracy.
The Potential Was There but TI Didn't Deliver 
2008-03-04
After having used the TI-89 Titanium for a couple of years, I have discarded it for the older HP48GX. I have found that I prefer the Reverse Polish input of method of the HP but the TI-89 has a number of other problems.
1) Yes, it is a very powerful machine. However, Texas Instruments did not see fit to provide an Equation Writer: attempting to input complex equations on the Command Line is a real PITA. Once you get the equation input, you will see it displayed in "Pretty Print" which means that it now looks like a written equation but you can't do that in the first place.
2) The TI-89 Ti is not programmed out of the box to handle vectors. The target market has to include a lot of engineering students that would like that feature. The HP48GX on the other hand, with a push of a button can give me the dot product, cross product, magnitude, etc, etc.
3) Without an Equation Writer, the syntax to get differentials, integrals, etc takes some getting used to.
4) The manual supplied with the calculator is terse to the point of being cryptic in showing how to input more advanced mathematical techniques. However, that seems to be an industry wide problem because of the costs of producing and printing paper manuals.
5) The contrast with the silver gray background and the blue and yellow lettering for the secondary and tertiary functions is poor. Additionally, the letters are very small and difficult to see in the first place.
6) The contrast of the screen sucks! If you're the wrong side of 40 and wearing bifocals, good luck in trying to read a dialog box. TI should have also provided a magnifying glass.
Over-all, this is a very powerful calculator and some of the problems can be corrected with add-on programs. But...my decade-old HP48GX has features that TI did not see fit to put on a more "modern" machine. The TI-89 Ti has the horsepower but it is not harnessed effectively.
Good symbolic math for a handheld 2008-06-14
I'm a grad student in physical chemistry and I use it a lot, both for my symbolic calculations, as well as my numerical ones.
It's powerful, and has many functions - excellent for linear algebra, symbolic integration even on some improper integrals (the ones with infinite boundaries that converge), Fourier transforms, equation solving of any kind, differential equation solving, symbolic differentiation, complex number arithmetic, number base conversions, etc. For some functions that do not exist, you can download a program in TI BASIC off of many websites or write your own code in C and compile it in TI-GCC, the TI compiler, and put it on the calculator.
User support is the best in the market, because TI is a very popular brand and many people own as their high end handheld calculator either this or the simpler TI-89, with which the Titanium is entirely compatible. Its user manual is decent and provides a good introduction to a beginner. Besides, a simple search on the many support forums will answer any questions.
Like with all handhelds, the bottleneck is generally the user input speed, not the calculator's speed. Nevertheless, this calculator has the slight disadvantage of being rather slow for complex operations which the user can automate, because it's running on a 16 MHz ARM processor. Graphics are very slow for the levels of complexity that my figures require, so I don't even bother with it on the TI 89 Titanium. For those tasks, you're better off using Mathematica or Matlab on your computer. Remember this is a handheld calculator, not some supercomputer.
In summary:
PROS:
1. good user support;
2. many add-on programs available;
3. easy to create your own programs, especially in C;
4. good diversity of pre-installed commands: calculus, linear algebra, spreadsheet capability;
5. large screen (if not largest in this category);
6. easy to master (took me 2 weeks).
CONS:
1. slower than others on the market, like HP 50g, although you might not necessarily notice;
2. lack of a real equation editor - you must type your formulas in on one line, which leads me to lose track of parenthesis matching sometimes.
Fantastic 2008-06-02
If you can find something it won't do and do well, your ready to take over for Stephen Hawking.
Excellent calculator.
Excellent product and service 2008-04-15
All expectations were accomplished with this product. Excellent for post graduated studies in engineering, which is what it is being used for. Internet utilities are good and easy to get.
TI-89 2008-04-06
Be careful shopping for the TI-89! There are several different versions of the same model. Make sure that the USB cable comes with the calculator so you can connect to the computer and update etc. The cable will cost you another twenty dollars seperatley.
T-92 a little better 2008-04-05
While a ti-92 and a t-89 have the same functionality, the qwerty keyboard on the ti-92 is the only thing I miss. This calculator is a must have for advanced chemistry and calculus.
