级数(n^(n+1/n))/((n+1/n)^n)的敛散性的怎么判断
问题描述:
级数(n^(n+1/n))/((n+1/n)^n)的敛散性的怎么判断
答
limit{n->∞}(n^(n+1/n))/((n+1/n)^n)=limit{n->∞}[n/(n+1/n)]^n*n*(1/n)=limit{n->∞}[1/(1+1/n^2)]^n*limit{n->∞}n*(1/n)=1/limit{n->∞}exp[n*ln(1+1/n^2)]*limit{n->∞}exp[(1/n)*lnn]=1/limit{n->∞}exp(n*1/...