第13题求解!
1个回答
展开全部
1/n(n+1)(n+2)
=[1/n(n+1)-1/(n+1)(n+2)]/2
=[1/n-1/(n+1)-1/(n+1)+1/(n+2)]/2
原式左边={[1-1/2-1/2+1/3]+[1/2-1/3-1/3+1/4]+……+[1/n-1/(n+1)-1/(n+1)+1/(n+2)]}/2
=[1-1/2-1/(n+1)+1/(n+2)]/2
=1/4-[1/(n+1)-1/(n+2)]/2
<1/4
哪里不懂请问,没问题请采纳~~~~~~~~~~~~~
=[1/n(n+1)-1/(n+1)(n+2)]/2
=[1/n-1/(n+1)-1/(n+1)+1/(n+2)]/2
原式左边={[1-1/2-1/2+1/3]+[1/2-1/3-1/3+1/4]+……+[1/n-1/(n+1)-1/(n+1)+1/(n+2)]}/2
=[1-1/2-1/(n+1)+1/(n+2)]/2
=1/4-[1/(n+1)-1/(n+2)]/2
<1/4
哪里不懂请问,没问题请采纳~~~~~~~~~~~~~
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询