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若存在正数x使2x(x-a)<1成立,则a的取值范围是( ) A.(-∞,+∞)...
若存在正数x使2x(x-a)<1成立,则a的取值范围是( )
A.(-∞,+∞)
B.(-2,+∞)
C.(0,+∞)
D.(-1,+∞)
考点分析:
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