Hello there, I'm a community college student in Pre Calculus who just received a C on his midterm and does not want to lose his GPA. Not knowing anything about calculators, I decided that the TI85 must obviously be superior to the suggested TI83 since the number was bigger. However, I've come to learn that the 85 is actually older and has fewer functions than the TI83 or 84--so much so, in fact, that it's beginning to hinder my home work and general participation in the class. Now, I recognize that just because I cannot find the calculator's features using the instructions given for the newer models, does not mean that it does not have identicle or at least comparable features.

Some basic questions regarding the TI85 are as follows:
1.) Is there a way to quickly, accurately find the x-intercepts?
2.) Is there a way to quickly, accurately find the extrema?
3.) Once a program is entered into the calculator (such as the Quadratic formula), how does one apply it?
4.) Is there a way to force the calculator to use complex numbers?

Thanks in advance. These are just the problems I've been having off the top of my head; I may well need more advice soon.