Question

4求f()=lnx在区间[13]上满足拉格朗日中值定理的点

Answer 1

f(x)=lnx在区间[13]上满足拉格朗日中值定理的点a=2/ln3

Answer 2

f(x)=lnx
f(3)=ln3, f(1)=0, f'(a) = (ln3-ln1)/(3-1)=ln3/2
f'(x)=1/x =ln3/2
x=a=2/ln3