︳x+1︳+︳x-1︳>2-a对x∈R恒成立,2-a＜（︳x+1︳+︳x-1︳）min=2所以a＞01+ax≤0即x≤-1/a时肯定成立,因为负数小于根号1+ax≥0即x≥-1/a时平方得x^2+1≥ax^2+2ax+1,（a-1）x^2+2ax≤0,x[(a-1)x+2a]≤0a=1时x≤0,a≠...