TI-89: Unbelievable power?

Lets face it: we live in a technological age. I am extremely reliant on my calculator, and most math classes nowadays are intensively calculator based. I agree that it is somewhat pathetic. I cannot image how people took calculus and other high level math before graphing calculators became the standard. However, being that this is the way things are, it is extremely important for a math student to have a powerful, easy to use and reliable calculator. The TI-89 fits this bill.

After using a TI-83 plus for two and a half years, I felt like I had exhausted its usage and needed something more powerful, so I upgraded to the TI-89. Since that time, I have used the TI-89 in various calculus, chemistry and physics classes for over a year and overall I have been very satisfied.

In terms of functionality, the TI-89 can do almost everything I can think of. Obviously it can do most things that the TI-83 can do such as function, parametric, polar and sequence graphing, and regression models and plots. The TI-89 also has a feature called pretty print which allows it to shows calculations in standard mathematics notation. Also, the output from the 89 is in rational numbers such as fractions and square roots, instead of as decimal approximations as is in the TI-83. Other notable features on the TI-89 include vector operations, a statistics editor, and support for different base number systems such as binary and hexadecimal.

The biggest thing that sets the TI-89 apart from lesser calculators is its computer algebra system. A version of Texas Instrument’s Derive software is integrated into the 89. This system allows the calculator to “do” math symbolically, the why a human can, instead of numerically - i.e. guessing really fast, the way most calculators operate. Thus, the TI-89 has all the functions to solve equations, factor polynomials and expand functions on the fly. The computer algebra system can be applied to calculus too. The calculator can find derivatives, integrals, limits and series quickly and easily.

The other big feature of the TI-89 is its 3-D graphing capabilities. While this may sound impressive to the layman, the truth is the 89’s 3-D graphing is severely limited by its processing speed and screen resolution, thus it is not that useful. A simple 3-D graph takes about 10 seconds to generate, while a more complex one may take up to one minute. Add to that the fact that the graph must be regenerated every time you change the window, and that’s a lot of waiting. While some graphs look pretty nice, others are almost unrecognizable on the 89’s small screen. Complex multivariable functions can be loaded almost instantaneously on various computer based math software such as Mathcad or Converge, and those graphs on a large computer monitor are much easier to analyze. Still, having the power to do 3-D graphing at your fingertips on a probable calculator can be handy sometimes, in the sense that it’s better then nothing. If I have the choice, I’d still use computer based system for my 3-D graphing needs.

The expandability of all Texas Instruments calculators is very good. It is easy to download from a computer to the calculator, however, the cable that is needed is sold separately. On the TI-89, programs, applications, and new operating systems can be downloaded and installed. There is plenty of RAM and Flash ROM memory to fit these add-ons. It is also easy to write your own programs on the TI-89. The program editor on the 89 has a find function to navigate through code more easily, the ability to pass and return variables to functions, and the ability to write comments. There features combined with the higher resolution screen make programming straight into the TI-89 much easier then on the TI-83.

Although the screen on the TI-89 is much higher resolution then the TI-83, the size of the screen is the same. The font size on the 89 is small, so it is sometimes a strain on my eyes. The TI-92 is the same internally as the TI-89, but has a bigger higher resolution screen and a qwerty keyboard. However, it is more expensive and cannot be used on examinations such as the SATs. Another complaint I have about the TI-89 is that some common functions that I use, such as the e constant and base 10 log are not quickly accessible as a button on the keyboard, and can only be used by searching through the catalog or math menus.

Overall, the switch from the 83 to the 89 has been easier then I expected. This is partially because the TI-89 has the same button layout as the TI-83. The buttons are fast and easy to use, although some buttons such as the brackets, comma, and square root buttons are located in different places. The TI-89 with the Advanced Mathematics software, has a menu based interface. If you are new to this type of interface, it could take some time getting used to. However, once learned the menu interface is a quick and appropriate way to utilize the many functions of the TI-89.

The only other calculator on the market that can compare with the TI-89 is the HP48gx/HP49g. Many people prefer the HP over the TI-89. The HP uses a stack system that is completely different from the TI, and difficult to learn, but it has some advantages. I have heard that the HP has more functionality in engineering. The HP49g and HP48gx can also be found for cheaper then the TI-89. However, I chose the TI-89 over the HP because of its ease of use and due to my overall good experience with the TI-83. Still the HP calculator is worth a look.

The TI-89 can be an extremely powerful tool. I used to believe that ones calculator was not that important. I thought that brainpower was all that could get one a high grade. Although I still believe that the calculator is only as smart as its owner, a student that has a more powerful calculator will without a doubt have an unfair advantage. I can honestly say if I had this calculator starting from algebra I I would have aced all my math courses; Instead I got B's.