对分母使用微分中值定理。
lim(n趋向于无穷) n^afa/{[n-(n-1)]*[n^(beta-1)*(n-1)^0+n^(beta-2)*(n-1)^1+...+n^(0)*(n-1)^(beta-1)]}
=lim(n趋向于无穷) n^afa/[n^(beta-1)*(n-1)^0+n^(beta-2)*(n-1)^1+...+n^(0)*(n-1)^(beta-1)]
上下式同除以,n^afa
=lim(n趋向于无穷)1 /[n^(beta-1)*(n-1)^0/n^afa+n^(beta-2)*(n-1)^1/n^afa+...+n^(0)*(n-1)^(beta-1)/n^afa]
因此此极限存在,并且不为零为2016,则,
n^(beta-i)*(n-1)^(i-1)/n^afa,每个个都存在极限
afa=beta-i+i-1=beta-1
1/beta=2016
则beta=1/2016
afa=2015/2016