若m=2,则-1>0,不成立,符合解集为空集 若m=-2,则-4x-1>0,解集不是空集 若m≠±2,则这时二次不等式,大于0的解集为空集 所以(m^2-4)x^2+(m-2)x-1<=0恒成立 则开口向下,m^2-4<0,(m+2)(m-2)<0,-2<2 且判别式小于等于0 (m-2)^2+4(m^2-4)<=0 (m-2)^2+4(m+2)(m-2)<=0 (m-2)[(m-2)+4(m+2)]<=0 (m-2)(5m+6)<=0 -6/5<=m<=2 要符合-2<2 所以-6/5<=m<2 综上 -6/5≤m≤2