I got a ti89 in high school cause my friend got one, and i needed a graphing calculator to fit in...cause everyone had those ti83 and i wanted one to so i could play games...cause a calculator that can play games is cool somehow... Anyways my friend got a ti89, and when i saw the kinda games that thing i could play... i knew i had to have one to... when i bought it, i could of had a ti92...the price was same cause store was going out of buisness, but i wouldn't of been allowed to use a ti92 on any real test like sat...
anyway to sum it up... i didn't know about the ti89's abilities to factor and expand and do derivatives and integrals and solve stuff like this solve(x + 2 = 3,x) and it tells me x = 1... or more complicated situations like solve(x+y = 1 and x = 1,x) and it says x = 1 and y = 1...
So anways as i got into higher and higher math, i learned more and more about what it could do... even in college I'm still finding out about things it can do.
o yea, did i mention i was using a ti89 when i was like a sophmore in high school... was great in algebra 2 and trignometry and geometry... was made even better cause i had the black link cable (so i could send games to it) which allowed me to send math programs to it... some of which i had on the thing since i downloaded them years ago...and still getting use out of them!
I really suggest you get a ti89 titanium... it has a faster processor and more memory then my hardware version 1 original ti89. Also it can use a regular usb cable to send files to it.
I can't stress this enough...you are going to need a ti89 in college... it will help you learn... and a ti89 needs years to stumble through all it's features so sooner you get it the better.
I should also add that in college, I'm not allowed any calculator on any math exam! and I've had lots of them, however physics let's me use a ti89, or any calculator... they say its cause physics is not a test of your math solving capabilities... it's about your capability to do physics.
Did i mention...get a ti89 titanium!
o yea you totally need to get this program on ti89 asap, if you get one:
http://www.technicalc.org/packages/eqw/eqw.htm
its a program for symbolic entering of math formulas... bets pants off of doing it manually for let's say, a 3x3 matrix... god linear algebra sucks with all the matrixes :P