设N∈N*,利用放缩法证明1/(n+1)+1/(n+2)+1/(n+3) +……+1/3n
题目
设N∈N*,利用放缩法证明1/(n+1)+1/(n+2)+1/(n+3) +……+1/3n
答案
1/(n+1)+1/(n+2)+1/(n+3)+······+1/(3n)
<1/(n+1)+1/(n+1)+1/(n+1)+······+1/(n+1)
=[3n-(n+1)]/(n+1)
=(2n-1)/(n+1)
<(2n+2)/(n+1)
=2
举一反三
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点