Why would someone wants to jump to substitution rule when he said he has not come across L'Hopital's rule! ==== where is that coming from ????? :S :S :S L hospitals rule is the simplest of all to solve that problem filip folop. it solves in two steps as u did. Substitution???? i see what u saying. the chain rule rite? well that was for his second part. remember, pat had two problems 1) lim (e^x-1)/x =1 x-o 2) derivative of e^x w.r.t. x is e^x My last post was for this part. Loote