问题
选择题
若关于x不等式2x2+ax+2＜0的解集为∅，则实数a满足（ ）
A．a＞4或a＜-4
B．a≥4或a≤-4
C．-4＜a＜4
D．-4≤a≤4
答案
因为关于x不等式2x2+ax+2＜0的解集为∅，
所以a2-4×2×2≤0，解得-4≤a≤4．
故选D．
搜题请搜索小程序“爱下问搜题”
若关于x不等式2x2+ax+2＜0的解集为∅，则实数a满足（ ）
A．a＞4或a＜-4
B．a≥4或a≤-4
C．-4＜a＜4
D．-4≤a≤4
因为关于x不等式2x2+ax+2＜0的解集为∅，
所以a2-4×2×2≤0，解得-4≤a≤4．
故选D．
选用方框内所给词的适当形式填空。
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