Hi, Since it's just a couple of days left of a mini-`contest' our maths teacher has announced, and since she said it was 100% OK to get help from other people (and because I'm lazy and don't want to search mathematical literature everywhere :-P ), here comes a question: When f(x) = 0, the graph crosses the X axis. When f'(x) = 0, the graph is at its top or bottom. When f''(x) = 0, the graph is at what we in Norwegian call a `turning point' -- I don't know the proper English term :-) How does a graph look like when f'''(x) = 0? I mean, I can plot a few graphs and see that it is somewhere between f'(x) and f''(x), but I don't see anything striking... Our teacher also mentioned a (female) mathematician finding these points and subsequently gotten them named after herself -- I'm sure this would be worth some bonus points ;-) Does anybody know, and more importantly -- can you _explain_ it? (One of the hardest things here would be that graphs don't go well in ASCII, I'd guess ;-) ) /* Steinar */ -- Homepage: http://members.xoom.com/sneeze/ _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers