I'm soliciting thoughts on this program. This is where I'm coming from (for now): I am self-teaching myself math. I've always been good at math (according to my grades), but never went beyond Precalc. I am now reviewing my precalc book, page by page, exercise by exercise, skipping nothing. By the end of the year, I should be starting Calculus. If I have to take a course to get the benefit of an instructor, I will, but I don't think I'll need to. As I go along, and being aware of calculators (like the TI-89, which I have), and math programs (like Mathematica), it seems that justification for *solving* a problem by hand boils down to "I should know how the solution is arrived at, that way the answer won't just seem like a magic trick". I can deal with that, but at some point in time I'm pretty sure that I will simply no longer want to work out the answers. Recognizing problems and understanding the relationships of the variables and quantities such that I can *define* the problem is what will give me satisfaction. And I'll be more than happy to let a program figure out the solutions. Any thoughts on Mathematica?