why in the world would you need an 89 for pre calc?? What kind of material does the teacher want to teach??
but anyways, if the teacher says so, then I guess do what the teacher says. But to answer teh question, the 85 *should * be able to do what a typical pre-calc class covers(unless your teachers's idea of pre calc is integerals, Derivates, Differentail equations etc etc).
Yea, the 89 and 85 is like night and day. I had trouble gettng used to the 89 myself. W/ earlier calculators, you punch in a number and push the equal sign. w/ the 89, you go to file > blah > calculus > find Derivative etc etc etc. You work it like a computer program.
But if the teacher reccommends the 89 and is willing to take the time to teach it to you guys, then I would just get it if you plan on higher math.
btw, my pre calc covered Trigonometry and very very basic limits. Is that what your pre calc is??