填空题若命题“?x∈R,使得x2+(a-1)x+1≤0”为假命题,则实数a的范围________.
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(-1,3)解析分析:不等式对应的是二次函数,其开口向上,若“?x∈R,使得x2+(a-1)x+1≤0”,则相应二次方程有实根.求出a的范围,然后求解命题“?x∈R,使得x2+(a-1)x+1≤0”为假命题,实数a的范围.解答:∵“?x∈R,使得x2+(a-1)x+1≤0∴x2+(a-1)x+1=0有两个实根∴△=(a-1)2-4≥0∴a≤-1,a≥3,所以命题“?x∈R,使得x2+(a-1)x+1≤0”为假命题,则实数a的范围(-1,3).故