问题描述: C(0,0)+1/2C(1,n)+1/3C(2,n)+…1/kC(k-1,n)…+1/(n+1)C(n,n)=1/(n+1) 1个回答 分类:数学 2014-12-04 问题解答: 我来补答 证明:1/iC(i-1,n)=1/i*n!/(i-1)!*(n+1-i)!)=n!/(i!*(n-1+i)!)=1/(n+1)(n+1)!/(i!*(n+1-i)!)=1/(n+1)C(i,n+1)C(0,0)+1/2C(1,n)+1/3C(2,n)+…1/kC(k-1,n)…+1/(n+1)C(n,n)=1/(n+1)(C(0,n+1)+C(1,n+1).+C(n,n+1))=(2^(n+1)-1)/(n+1)题目出错了,具体做法请见上面,祝好~ 展开全文阅读