f(x)＝1/(1－3x)³.求导

f(x)＝1/(1－3x)³.求导
f(x)＝1/(1－3x)³.求导

f(x)＝1/(1－3x)³.求导
令t(x)=f(x)＝1－3x,则：
f(x)=1/t(x)
f'(x)={[t(x)]^(-1/3)}' * [t'(x)]
=(-1/3){[t(x)]^(-4/3)} * (-3)
=(1－3x)^(-4/3)

f(x)=1/(1-3x)^3
f'(x)=-1/[(1-3x)^3]^2 *3(1-3x)^2 *(-3)
=9(1-3x)^2/(1-3x)^6
=9/(1-3x)^4