f(x)为非0函数高数f(x+y)=f(x)f(y)当x=0-查字典问答网
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  f(x)为非0函数高数f(x+y)=f(x)f(y)当x=0时的导数为1证明f(x)的导数等于f(x)

  f(x)为非0函数高数f(x+y)=f(x)f(y)当x=0时的导数为1证明f(x)的导数等于f(x)

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2020-12-2606:39
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孔凡敏

  f(x+y)=f(x)f(y)

  putx=y=0

  f(0)=f(0)f(0)

  f(0)=1

  f'(x)=lim(y->0){[f(x+y)-f(x)]/y}

  =lim(y->0)[f(x)f(y)-f(x)]/y

  =f(x)lim(y->0)(f(y)-1)/y

  =f(x)lim(y->0)(f(0+y)-f(0))/y

  =f(x)f'(0)

  =f(x)#

2020-12-26 06:42:06
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