已知数列
的各项均为正整数,且
.记
,
,其中[a,b]表示ab的最小倍数,约定
.证明:
,并分别指出两个等号各自成立的条件.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29518f13a1ebc3fff8181c2d7cfba22f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e1fb10e071c27dc786d1719dfdae80b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3054bf72b49fd845186f00cec93b3eda.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/861dc0caac5c70143ecad3135894527a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba15ca3e5d1e8ebbb6040e14b9417801.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7fe8b3a75a0734fabaf9621f9da58d8.png)
2018高三·全国·竞赛 查看更多[1]
更新时间:2018-12-17 09:53:09
|
相似题推荐
解答题-问答题
|
较难
(0.4)
【推荐1】设
,定义
.
①求
的最小值;
②在
条件下,求
的最小值;
③在
条件下,求
的最小值,并加以证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4331a24db623aa0df9938c61f8fa009.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6027ab8f832cbfc2e0bf444aeaad92be.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b708c8dcb2d66eb2ce0b3718a9cd924a.png)
②在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e866871838e4579372bd56e1ff916d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b708c8dcb2d66eb2ce0b3718a9cd924a.png)
③在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1ba17b5724a5df1bc18fedab153f94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b708c8dcb2d66eb2ce0b3718a9cd924a.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
【推荐2】若
是一个由数字1,2,3,4,5,6,7,8,9组成的
位正整数,并同时满足如下两个条件:
(1)数字1,2,…,
在
中各出现两次;
(2)每两个相同的数字
之间恰有
个数字.
此时,我们称这样的正整数
为“好数”.例如,当
时,
可以是312 132.试确定满足条件的正整数
的值,并各写出一个相应的好数
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d51f9147b8265c0276c1f2c2659197.png)
(1)数字1,2,…,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
(2)每两个相同的数字
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b640c28d4f3afbf94d07ec2e4d98b06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
此时,我们称这样的正整数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
您最近一年使用:0次