Question

求这道题的解答过程

Answer 1

tanhx=[e^x-e^(-x)]/[e^+e^(-x)]
导数=[e^x+e^(-x)]/e^x+e^(-x) -
[e^-e^(-x)]²/[e^x+e^(-x)]²
最后整理得
1-tanh²x

Answer 2

f(x)=tanhx
=[e^x-e^(-x)]/[e^x+e^(-x)]
=[e^(2x)-1]/[e^(2x)+1]
=1-2/[e^(2x)+1]
f'(x)=(-2)*[-2e^(2x)]/[e^(2x)+1]^2
=4e^(2x)/[e^(2x)+1]^2