"1/3+1/7+1/15+1/31+……+1/[2*(n+1)-1]〈2/3"怎么证明啊?1/3+1/7+1/15+1/31+……+1/[2*(n+1)-1]〈2/3 怎么证明啊?题目具体忘记了,意思是:求证:1/a2+1/a3+1/a4+…+1/a(n+1)〈2/3 ,其中数列{an}的通项公式为an=1/(2*n-1)是2
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/04 23:00:02
![](/uploads/image/z/10261832-32-2.jpg?t=%221%2F3%2B1%2F7%2B1%2F15%2B1%2F31%2B%E2%80%A6%E2%80%A6%2B1%2F%5B2%2A%28n%2B1%29-1%5D%E3%80%882%2F3%22%E6%80%8E%E4%B9%88%E8%AF%81%E6%98%8E%E5%95%8A%3F1%2F3%2B1%2F7%2B1%2F15%2B1%2F31%2B%E2%80%A6%E2%80%A6%2B1%2F%5B2%2A%28n%2B1%29-1%5D%E3%80%882%2F3++++%E6%80%8E%E4%B9%88%E8%AF%81%E6%98%8E%E5%95%8A%3F%E9%A2%98%E7%9B%AE%E5%85%B7%E4%BD%93%E5%BF%98%E8%AE%B0%E4%BA%86%2C%E6%84%8F%E6%80%9D%E6%98%AF%3A%E6%B1%82%E8%AF%81%3A1%2Fa2%2B1%2Fa3%2B1%2Fa4%2B%E2%80%A6%2B1%2Fa%28n%2B1%29%E3%80%882%2F3+%2C%E5%85%B6%E4%B8%AD%E6%95%B0%E5%88%97%7Ban%7D%E7%9A%84%E9%80%9A%E9%A1%B9%E5%85%AC%E5%BC%8F%E4%B8%BAan%3D1%2F%282%2An-1%29%E6%98%AF2)
"1/3+1/7+1/15+1/31+……+1/[2*(n+1)-1]〈2/3"怎么证明啊?1/3+1/7+1/15+1/31+……+1/[2*(n+1)-1]〈2/3 怎么证明啊?题目具体忘记了,意思是:求证:1/a2+1/a3+1/a4+…+1/a(n+1)〈2/3 ,其中数列{an}的通项公式为an=1/(2*n-1)是2
"1/3+1/7+1/15+1/31+……+1/[2*(n+1)-1]〈2/3"怎么证明啊?
1/3+1/7+1/15+1/31+……+1/[2*(n+1)-1]〈2/3 怎么证明啊?
题目具体忘记了,意思是:
求证:1/a2+1/a3+1/a4+…+1/a(n+1)〈2/3 ,
其中数列{an}的通项公式为an=1/(2*n-1)
是2的N+1次方再-1,打错符号了,*号应该是^号,感谢wxh240330提出来!
"1/3+1/7+1/15+1/31+……+1/[2*(n+1)-1]〈2/3"怎么证明啊?1/3+1/7+1/15+1/31+……+1/[2*(n+1)-1]〈2/3 怎么证明啊?题目具体忘记了,意思是:求证:1/a2+1/a3+1/a4+…+1/a(n+1)〈2/3 ,其中数列{an}的通项公式为an=1/(2*n-1)是2
n>1时,2^(n+1)-2^n-2^(n-1)=2^n-2^(n-1)=2^(n-1)>1,
2^(n+1)-1>2^n+2^(n-1)=3*2^(n-1),
1/[2^(n+1)-1]<1/[3*2^(n-1)],
1/3+1/7+1/15+1/31+……+1/[2^(n+1)-1]
<1/3+1/6+1/12+1/24+...+1/[3*2^(n-1)]
<2/3.
an=1/(2*n-1)还是an=1/(2^n-1) ???