f(x)=x^2-+x-1复合函数求f[f(lnx)]=(ln^2x+lnx-1)^2+(ln^2x+lnx-1)-1怎么算到=ln^4x+2ln^3x-lnx-1求详细
问题描述:
f(x)=x^2-+x-1复合函数求f[f(lnx)]=(ln^2x+lnx-1)^2+(ln^2x+lnx-1)-1怎么算到=ln^4x+2ln^3x-lnx-1求详细
答
f[f(lnx)]=(ln^2x+lnx-1)^2+(ln^2x+lnx-1)-1=(ln^2x+lnx-1)(ln^2x+lnx-1+1)-1=(ln^2x+lnx-1)(ln^2x+lnx)-1=ln^4x+ln^3x-ln^2x+ln^3x+ln^2x-lnx-1=ln^4x+2ln^3x-lnx-1请点击下面的【选为满意回答】按钮,...