## TI-89 Graphing Calculator Review

The TI-89 is a powerful calculator with a swiss-army-knife-esque ability to be many things at once. Not only will this calculator allow you to do all the regular things graphing calculators can do (calculate complicated lines of equations, graph functions and solve for intercepts, roots and much, much more, it also allows you to graph in 3-D and comes preloaded with a number of programs that can be used specifically for certain courses or subjects. It even has a calendar and agenda function in its main menu. But do you need all these functions? Letâ€™s dig a little deeper into the TI-89 and compare it to its cousins in the TI-83-86 lineups.

### Is a TI-89 better than a TI-84?

No, not necessarily. The majority of students and parents think that because it has a higher number, it must be a newer and therefore, better calculator. This could not be further from the truth. As we mentioned in our Ultimate Guide, the graphing calculator has to be the right fit for you. For many high school students, the TI-89 simply has too many functions to really be useful. For high school math, science and calculus classes, the TI-83-86 are probably entirely sufficient. The TI-89 is definitely a more grownup calculator but it is certainly more computer-like than its simpler predecessors. And to even call the TI-83-86 a predecessor to the TI-89 is a bit of a mistake anyway. The TI-84 line, for example, has multiple editions, and the latest one, the TI-84 +CE is newer, more powerful, and easier to use than the TI-89. The higher model number is more of a reflection of how many extra functions it has, not how fast or powerful it is. We would probably recommend the TI-89 over the TI-84 or TI-84 + for most students, but the TI-84 +C Silver Edition and the previously mentioned +CE are probably better choices in the price range of the TI-89.

### A calendar app on a Texas Instruments Graphing Calculator?

We mentioned above that the TI-89 Titanium has a celandar and agenda function. Youâ€™re probably asking yourselfÂ .Â Â .Â Â .Â Â *why?* If youâ€™re a student or teacher who is into using a calendar or agenda, chances are youâ€™re already using a moleskine planner, wall calendar, or mobile app such as iCal or Google Calendar. So, you probably wonâ€™t have much use for a black and white calendar app on your graphing calculator. We mention the calendar app because it is just one example of the TI-89 trying to do a little bit too much. While it is an excellent calculator in its own right, the many functions, menus and extra buttons (which all have three functions mapped to them) make the calculator feel a bit bloated. It certainly is a bit daunting to get used to where everything is at first, and as a result, the TI-89 Titanium has a steep learning curve, especially if youâ€™re used to a TI-83, TI-84 or TI-86.

## How does it behave as a calculator?

### Using the trig functions on the TI-89 Titanium graphing calculator

As a graphing calculator, the TI-89 certainly has some drawbacks. For example, to simply type SIN, COS or TAN, you need to use the 2^{nd} function. This is almost inexcusable. The calculator is also extremely unforgiving in terms of placing brackets at the ends of functions, such as when using one of the trig functions. For instance, on a TI-89, to evaluate sin(30Â°), you have to press 2^{nd}, SIN, 3-0, and then ), followed by ENTER. That is six buttons to evaluate a simple sine ratio, and if you forget the bracket (or closing parentheses to be exact) then you will get a syntax error and have to re-enter it. On a simpler calculator, like the user-friendly TI-84â€™s, you simply press SIN, 3-0, ENTER, and you donâ€™t need to close the bracket. The calculator takes a guess that SIN(30 was supposed to be SIN(30), and you get your result you wanted.Â It might seem nitpicky, but when youâ€™re studying, writing assignments, quizzes and tests in the trigonometry unit, you will certainly notice it.

### Using the Exponent, EXP, or EE button on a graphing calculator

As an example of something the TI-89 Titanium got right, letâ€™s take a look at how we enter numbers using scientific notation. The EE button is essential for physics, astronomy, and chemistry courses. While descriptions vary as to what the letters actually stand for (weâ€™ve seen Engineering Exponent as well as Enter Exponent), the button is great for working with both the very large numbers of physics and astronomy, and the very small numbers of physics and chemistry. It essentially enters , where you can then enter your exponent. So for example, entering the number 500,000,000 can be done by typing â€ś5â€ť â€śEEâ€ť â€ś8â€ť. Only three buttons instead of the nine it would have taken to type it out manually. And of course, how else would anybody make use of Avogadroâ€™s number? (Â â€“ thatâ€™s a number that has 24 digits in it by the way, and is used commonly in high school and college chemistry courses.) On some calculators, the EXP or EE button is hidden as a second function, and becomes a pain when doing calculations in these types of courses. Fortunately, at least the EE button on the TI-89 is not one of these types. Perhaps they figured that most users of the TI-89 wouldnâ€™t care about sine, cosine, and tangent, but they obviously recognized that engineers, physicists and chemists would be interested in it, and rightfully put the EE button on its own first function of a button, as it should be.

### The Final Two Cents

The TI-89 Titanium Edition is an excellent graphing calculator with an incredibly diverse array of functions and capabilities. It has a few quirks and challenging components about it, so we canâ€™t recommend this as an entry-level graphing calculator for a high school student, but for an advanced user, it really is a nice calculator. That being said, in this price range, the newly-released TI-84 +CE is a better buy. If you absolutely need to have all the functions the TI-89 offers, and you actually know how to use them, then this is certainly worth giving a try. Perhaps see if you can get your hands on one from a friend or colleague, and play around with it for awhile to see if you like the way it functions. This is a fine calculator, but certainly intended for a smaller market than the TI-84 or TI-NSpire lines.

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