x-2+1/x的单调递增区间（-∞,-1）∪（1,+∞）；单调递减区间（-1,0）∪（0,1）∵a²-4(a-1)=a²-4a+4=（a-2)²≥0∴a²≥4(a-1)∵a>1∴a≥2√(a-1) 当x>0时,x-a+(a-1)/x≥2√[x×(a-1)/x]-a=2√(a-1...