I was searching for the proof of \frac{d}{dx} e^x = e^x.
and I found one in yahoo knowledge saying that
\frac{d}{dx} e^x = \lim_{Δx\to 0} \frac {e^x(e^{Δx}-1)} {Δx}
= \lim_{Δx\to 0} \frac {e^x [\lim_{n\to\infty} (1+ \frac{1}{n})^{n(Δx)}-1]} {Δx}
Let h= \frac {1}{n} , So that n = \frac...