hello,

i don't know how to do proving the existence of e ....

okay, i know that it is by definition :

$\displaystyle \displaystyle e = \lim_{n\to \infty} (1+\frac {1}{n})^n $

or

$\displaystyle \displaystyle e = \sum_{n=0} ^{\infty} \frac {1}{n!} $

I have no idea how to do it, can some one help me with these please :D

P.S. I'm really really sorry if this shouldn't be posted here :D