y=1/x有界吗
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y=1/x有界吗
y=1/x有界吗
y=1/x有界吗
显然没有的,
证 假设有界,存在正数M,使得对于任意x,|f(x)|0时,总有1/x=1.
取x=1/(M+1),代入上式,得(M)/(M+1)>=1,显然错误,
所以假设错误,
故无界.
y=1/x有界吗
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