Well, I love calculus. But sometimes, its confusing. Ever been though a time while you haven't been to a single calc class, and just learn it all though reading a textbook not being able to ask questions? It's hard. I'm having a problem. f (x) = (integral sign) F(x) dx I don't understand the constant of integration, and why it can be anything. but the main problem here is whast the difference between an indefinite integral and a definite integral with dx? I know the integral sign from a to b dx means all the infinitely small pieces of x added together. But I don't understand the integral sign and dx together without area, like the above example. What does x stand for? Since this is a function of f(x), if it was f(t) would it be dt? Would this just mean the "change in" aka delta t? And i asked my teacher at my school what the difference between dx and dx/x is, but I forgot already :( Thanks for the help, I wish I would have known of this forum earlier.