Trying to derive an equation for f from df(x)/dx = f(x), f(0) = 1 Let g(x) = lim{n→∞} (1+x/n)^n g(0) = 1 dg(x)/dx = d/dx lim{n→∞} (1+x/n)^n = lim{n→∞} d/dx (1+x/n)^n = lim{n→∞} n * (1+x/n)^(n-1) * (1/n) = lim{n→∞} (1+x/n)^n / (1+x/n)