f(x)=lnx-ax+(1-a)/xf'(x)=1/x-a+(a-1)/x² =[-ax²+x+(a-1)]/x²=-a[x²-1/a*x+(1/a-1)]/x²=-a(x-1)[x-(1/a-1)]/x² 当a=1/2时,1/a-1=1f'(x)=-1/2(x-1)²/x²≤0恒成...