limx->1时,(ln x)^(x-1),请朋友们说下过程吧,

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limx->1时,(ln x)^(x-1),请朋友们说下过程吧,
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limx->1时,(ln x)^(x-1),请朋友们说下过程吧,
limx->1时,(ln x)^(x-1),请朋友们说下过程吧,

limx->1时,(ln x)^(x-1),请朋友们说下过程吧,
这是0^∞型极限,变形后可用洛必达法则求
lim(x→1)(lnx)^(x-1)=lim(x→1)e^(ln(lnx)^(x-1))=lim(x→1)e^[(x-1)(ln(lnx))]
=lim(x→1)e^[ln(lnx)/(1/(x-1))]=lim(x→1)e^[(1/xlnx)/(-1/(x-1)²)](分子分母同时求导)
=lim(x→1)e^[(x-1)²/(xlnx)]=lim(x→1)e^2(x-1)/(lnx+1))(分子分母同时求导)
=lim(x→1)e^0=1

lnx^(x-1)=(x-1)lnx 当X趋近于1时 (x-1)趋近于0 lnx也趋近于0 所以(x-1)lnx趋近于0

当x-->1时,lnx=ln(1+x-1)与x-1等价,所以利用等价无穷小的替换得
lim(x-->1)[x/(x-1)] /(1/lnx)=lim(x-->1)(xlnx)/(x-1)
=lim(x-->1)(x(x-1))/(x-1) =lim(x-->1)x=1.