>> I forgot what it was in the exam. So I just derived it from definitions. Hah, I did the same :-) ... unfortunately I also forgot the conventional names, and

>> I forgot what it was in the exam. So I just derived it from definitions. Hah, I did the same :-) ... unfortunately I also forgot the conventional names, and just used 's' (for speed) instead of 'v', and 'd' (for distance) instead of 's'. My teacher did not object the derivation at all, but told me that the results are wrong, because of the letters used ... Well, point taken - now, I try to pay extra attention and memorize idiosyncrasies like naming conventions ... it saves time when communicating with others.