I was reading a scientific pager by Stephen Hawkings and there was a disclaimer on it saying "This paper is intended for people with university colleage level or higher." So, somewhere it says on there to e, something to do with the universe. I really don't understand e. I've heard log base e is equal to [tex]e^x[/tex]? I'm 16 in high school. Also, my question with derivatives. I was reading a very old book that was republished, in fact it was my first book about calculus. And it said whenever you have some deriviative such as [tex]dx^2[/tex] is negligible since dx is an infinitely small piece and that squared is negatve infinite squared, which is impossible? I also don't understand what the difference between [tex]dx[/tex] and [tex]dx/d[/tex] is. If you have [tex]dx/d[/tex] don't the d's cancel out? Or not? Thanks for the help.