1 . 九连环是中国一种古老的智力游戏,其结构如图,玩九连环就是要把这九个环全部从框架上解下或套上.研究发现,要解下第
个环,则必须先解下前面第
个环.用
表示解下
个环所需最少移动次数,用
表示前
个环都已经解下后,再解下第
个环所需次数,显然,
,
,且
.若要将第
个环解下,则必须先将第
个环套回框架,这个过程需要移动
次,这时再移动1次,就可以解下第
个环;然后再将第
个环解下,又需要移动
次.由此可得,
.据此计算![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2cd47b30a15a6ace20e2fc840a9add.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8c66acb7fc592b8474ab3f9d40a3590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e345e86daf74312a6992e5d1c3f47f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/702353dcd94e65036a199deced89f8a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c0cdbf7b7cb42491810101c6e0db4ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd310a4c39f1522cafacf1aeae19c3c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e181cdd42105f02e1a4446054ae65d34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96ae7d749ab38b1b10e27a535719e673.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c0cdbf7b7cb42491810101c6e0db4ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/908953401be1d145ed967572c8f6b753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c0cdbf7b7cb42491810101c6e0db4ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/908953401be1d145ed967572c8f6b753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7c07ac0804045aca56d41c17ee80ae2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2cd47b30a15a6ace20e2fc840a9add.png)
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解题方法
2 . 已知函数
,若
,不等式
在
上存在实数解,则实数
的取值范围_______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e375295cc768ca9b6a67574ed6744c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7ca9fb97b8f1c75a95f3e755f8ddbd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfaf5afd77bd894df1e1a672040de990.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed6d804ef44bfc64f824b0ccef71765e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
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