注意到：(1/3)^h-1=e^(-hln3)-1等价于-hln3y=(1/3)^xy'=lim[h→0] [f(x+h)-f(x)]/h=lim[h→0] [(1/3)^(x+h)-(1/3)^x]/h=lim[h→0] (1/3)^x[(1/3)^h-1]/h=lim[h→0] (1/3)^x[e^(-hln3)-1]/h=lim[h→0] (1/3)^x(-hln3)...