I recently heard that at a High School near me that TI-89's are required for multivariable calculus. Is there anything that makes a TI-89 different from other calcs? Or did my sister lie to me? :-/

The TI-89 series, along with the TI-92 series and the Voyage 200, support symbolic manipulation via the Derive computer algebra system. They can handle expressions/equations with variables in them, and do math with them. See this image and this page from TI about the Nspire vs. Nspire CAS.

Ah thanks! Well that certainly sounds helpful

Although it could be due to calculator functionality reasons, the more likely reason I think, is that TI struck a deal with the school in order to sell more calculators. I am sure that you could find a good offering from either Casio or HP that does what you need and more.

I don't think a public high school would be allowed to mandate a particular calculator due to a deal struck with a company. It's more likely that:
a) HP and Casio are not as popular / more recent, and thus aren't mentioned by the school, or
b) the coursework is designed around the functionality of the TI-89 series

Did you not go to a public school? I know what that is like. They allow lots of undesirable stuff I could go into a rant about common core and no child gets ahead (left behind as they say) and how easy even the "hardest" classes are but that is out of the scope of this topic. Why do you think that a public school would not allow such a thing especially if they get free calculators. Also I have seen teachers with special TI equipment for example overhead transparent graphing calculator (can't remember exact details) and yellow calculators that feature completely different cases, no this is not a case they added it is official. That means communication with people from TI surely happened. I do think their strategy is to give a few calculators, then due to the TI expectation for the classroom they more than makeup the loss.

TI does a lot of public outreach, which is a major contributing factor to the cost of their calculators. They spend a lot of money on designing curricula to use particular features of a calculator. HP and Casio don't do this nearly as often, if at all. Additionally, TI has incentivized the purchase of TI calculators, although this program is not used much at all. Yes, they do try to maximize their market share within the education field, and they have been very successful.

But I digress. The course most likely calls for a TI-89 since it is the most popular test-accepted calculator with a CAS, and it'd be rather wordy to list off a bunch of acceptable calculators. The course basically requires a computer algebra system but disallows devices with networking (eg. laptops). The 50g or the Prime would most certainly be accepted by the instructor; the ClassPads are often disallowed by instructors due to stylus-driven input, and it wouldn't make sense to purchase an expensive calculator that isn't allowed on any standardized test.

I notice another mention of "Common core" in one of your links. You see that is what is happening here the standards are designed to benefit companies by making their product standard thereby stamping out competition that would be had in a free market. Also notice the word common. You see they want to make people "common" or dumped down. One person involved in the standard refused to sign off on the standard as it does not even call for algebra II that is according to http://whatiscommoncore.wordpress.com/
I am embarrassed to admit that I doubled up algebra II and geometry during my softmore year both classes were prefixed with "advanced" however there appeared to be little difference between "advanced" and regular as still students did not care and the classes were very easy. The reason I did this was to make up for past mistakes that were made in middle school when I did not care about education and knowledge as much. I cannot imagine never taking algebra II in high school. Anyways yes I am ranting and getting a bit off topic and for that I apologize but I wish people would care more about education and it is key to success for whatever country you live in. Education should be far more valued than it is now and I just want people to critically analyze what is going on and think objectively to why such a policy might exist such as a TI calculator mandate (to benefit them). Also I hope that in case any younger members are reading this forum, that they continue to value their education and not take the easy way out which is very easy to do in a US public high school at least to my experience. I used to screw around in middle school and found that that impact me through high school due to missed opportunities that were taken care of in high school but had I cared earlier in middle school I would not have had to such things in high school. Also don't go repeating all this saying it is your teacher's fault, it is usually not and I do not want this post to drastically alter your perception of your school this is my personal experience and your mileage may vary. I believe that it is instead policy makers who have never been in a classroom since they went to school are to blame. Also if anyone is wondering why I first talk about how easy I found the hardest offered classes and then talk about valuing your education in school, it is because you will still learning a lot and it will still benefit you and you can use your free time to learn even more.

Thomas Jefferson High School for Science and Technology is not a public school. It's a big thing here and one must take the test to make it in. And from what I heard, students need to purchase their own calculator. As for the "no child left behind" at TJHSST if you get left behind you are basically screwed unless you spend 24/7 trying to catch up.

Well it is too late for any such thing like that and I don't live near there if you are suggesting a better alternative, a quick google search reveals that it sounds like a nice opportunity that I wish I would have had. I went to the wikipedia page and saw that they had a logo for their computer lab incorporating the linux mascot, now that is awesome. You are one lucky kid should you take the opportunity. Considering you are on this forum, I think you would like it there. I hope more schools become more like TJHSST. Also it is a public school, but a really good one from the looks of things and it appers to be ran more like a private school. I do wish there was a secular private school my area.

I sure do wish I have an opportunity to attend TJHSST but this year only 20 students from my middle school made it in. From what I ear the experiences at TJ are far more interesting than other High Schools in the area. I have begun rigorous test prep but I fear I may not be able to get in.

Do not fear the test, master the test. A negative attitude will not help you do well.
I believe you to be capable of getting in so do it but don't expect you to magically ace the test. With the rigorous test prep I am sure you have a chance.

My essays suck :-/ But thanks for the support

Recognizing what to improve is the first step towards improvement. Take action upon it.

You shouldn't actually need an 89....taking partial derivatives by hand is just as easy as taking single derivatives, and that's basically also true for the double/triple/line/surface/contour/etc integrals.