判定级数∑(n从1到∞)(n^(1/n)-n^(1/(n+1)))的敛散性.

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判定级数∑(n从1到∞)(n^(1/n)-n^(1/(n+1)))的敛散性.判定级数∑(n从1到∞)(n^(1/n)-n^(1/(n+1)))的敛散性.判定级数∑(n从1到∞)(n^(1/n)-n^(

判定级数∑(n从1到∞)(n^(1/n)-n^(1/(n+1)))的敛散性.
判定级数∑(n从1到∞)(n^(1/n)-n^(1/(n+1)))的敛散性.

判定级数∑(n从1到∞)(n^(1/n)-n^(1/(n+1)))的敛散性.
设f(x)=n^(1/x) ,an = f(n)-f(n+1),有拉格朗日定理,对足够大的n 有
|an| = f'(ξ)=n^(1/ξ)㏑n/x^2