天气预报15天查询> 其他> 证明数列为等差或等比数列技巧

证明数列为等差或等比数列技巧

更新时间： 2020-11-05 00:00:00

1、通常用定义法，等差数列：求证an-an-1为一个定值,则为等差数列。

2、等比数列：求证an/an-1为一个定值,则为等比数列.依题意,不妨设数列中连续3项为：a,aq,aq^2则：a-aq=aq-aq^2即：aq^2-2aq+a=0或：a*(q-1)^2=0所以只有：q=1

3、或者用中项法，等差数列：求证an+1+an-1=2an，等比数列：求证an+1*an-1=an平方

关键词：证明数列等差等比数列技巧

证明数列为等差或等比数列技巧相关经验

相关推荐

最热天气预报更多>

重点城市天气预报

最新天气资讯更多>

导航网址

如有意见、反馈、侵权或投诉等情况，请联系:

电话:

邮箱:

我们将会在48小时内给与处理！

版权所有 Copyright ? 2009-2020 tianqiyubao3.com

页面:/news/view-469524/ | 耗时:0.0283 s | 内存:1.89 MB | 查询:4 | 缓存读取:4 写入:0 | 加载文件:23
select * from tbl_Articles WHERE ArticleID=469524 LIMIT 0,1
select * from tbl_Articles_data WHERE ArticleID=469524 LIMIT 0,1
select * from tbl_Articles_sphinx where id=469524 LIMIT 0,1
SELECT ArticleID,Title FROM tbl_Articles WHERE ArticleID IN(166908,149682,129430,139066,116213,141433,2666590,168026,165510,295537,140294,144348,152817,181098,178768,150727,132429,174236,144343,147069,124480,132852,181819,1125323,179419,159715,1042490,149227,177218,152834) ORDER BY field (ArticleID,166908,149682,129430,139066,116213,141433,2666590,168026,165510,295537,140294,144348,152817,181098,178768,150727,132429,174236,144343,147069,124480,132852,181819,1125323,179419,159715,1042490,149227,177218,152834)