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设x>0,y>0,且xy-(x+y)=1,则( ) A.x+y≤2+2 B.x+...
设x>0,y>0,且xy-(x+y)=1,则( )
A.x+y≤2
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+2
B.x+y≥2
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+2
C.x+y≤(
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+1)
2D.x+y≥(
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+1)
2
考点分析:
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下列结论正确的是( )
A.当x>0且x≠1时,lgx+
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≥2
B.当x>0时,
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+
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≥2
C.当x≥2时,x+
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的最小值为2
D.当0<x≤2时,x-
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∈(-1,1),使f(x
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A.
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B.a<-1
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D.
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