TI-84 Part Deux

Well, I did a little reading in the manual (when I say little, I mean 15 minutes before I had to leave for class!) and I found what I needed to know for graphing functions. I found where it talked about the derivatives and I quickly learned what I should've known from classes I took in high school. Anyway, I learned how to put in the x-value of a point to find out if that point is on the graph (the first thing I need to know which tells me if I should proceed with the calculations or if I just have to say that the point isn't on the graph). Then I learned how to find the derivative using the "Calc" feature and made the conclusion that when I use that to find the derivative I also (without having to do all the computations) know what the slope of the tangent line is (if I have to find the slope of the tangent line at that point). I already knew how to input the function to get the graph, but these newfound insights will help me double check my work. It's been 5 years since I've been in a higher level math class, and I've found I don't remember it all. I wish now I would've taken Calculus as soon as I started college because I'd be way ahead of where I am now. But that's okay, I enjoyed my time before, the second time around has to be better right????