设函数在f(x)在(0,正无穷)内可导,且f(e ^x)=x+e^x,则f'(1)=设函数在f(x)在(0,正无穷)内可导,且f(e ^x)=x+e^x,则f'(1)=

问题描述:

设函数在f(x)在(0,正无穷)内可导,且f(e ^x)=x+e^x,则f'(1)=
设函数在f(x)在(0,正无穷)内可导,且f(e ^x)=x+e^x,则f'(1)=

由题意知:
f(x)=x+ln(x;
所以f'(x)=1+1/x;
则f'(1)=2;

f(e^x) = x + e^x,
f(t) = lnt + t,
f'(t) = 1/t + 1,
f'(1) = 1/1 + 1 = 2.