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已知符号函数sgn(x)=,则方程sgn(x)-lnx=0的实数根的个数为( )...
已知符号函数sgn(x)=
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,则方程sgn(x)-lnx=0的实数根的个数为( )
A.1
B.2
C.3
D.4
考点分析:
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