It's not that I'm a total beginner in mathematics, so please allow me to explain: I've worked through everything UNTIL Calculus, quite hard at that, when I was in college. I took a series of general physics courses, passed with no problem, and everything was good, EXCEPT... Years ago, I purchased a physics book (for about $4, though that's not important) hoping to work through it as well, but I left school. It has been some 4 years later, and I want to work through it, but it's calculus based. Problem is, I never had any formal schooling for Calculus (minus the introduction to limits in precalculus) and forget the overwhelming majority of mathematics from then. I know this seems lazy, and largely it is, and is asking much from the community, but knowing that I've done this before, what algebraic areas need I review before calculus, so that I may have a firm foundation for calculus? I say again, I've done it all before, but most I've forgotten as I haven't used it in years, so it's not as though you're telling a child to perform differentiation, and I made my way through the algebraic physics courses as well, but what is ABSOLUTELY ESSENTIAL so that I may review it all properly? I've always been poor on exponential functions, so I know those, but what else? I feel like occasionally I'm reviewing things that don't matter in my old books (completing the square? Quadratic equation) so I ask you guys, because I want to get back into it, but I don't think I need to take three more quarters worth of mathematics just to remember what I once knew. Probably a stupid question, I know, but I must ask it.