解题方法
1 . 已知
,求证
.某同学解这道题时,注意到结论中的三个量
,
,
.由已知条件得到
,
,
.进一步发现三者的关系:
.又观察左边式子的结构发现就是两个数的倒数和,从而联想到以前做过的题目“已知
,
,求证
”,类比其解法得到题目的解法:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f60d4d44e161c4c3e151ad73024a8228.png)
,当且仅当
时取等号.所以
.求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/497d269c30eec393e3f0e877ddbe2983.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/323f4e181b418a66cc36d75e0f8da126.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9f2416d1f75a45a314331146550832e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9db8d3facff8f90f28a936fc5b3ab878.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ea712984ea5017140e20bee226fd5af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/481ee0d1e39e92a4732eea90225eb94c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/936553b69099e03189581a42a5c1d8aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6e90787c63ca5b5f1a45e0f6e85aaa1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0c05be59bdd7874fd8e9ee5ba5b17f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67ca5fd57c2c2fcc3c7a574fdd1467d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86546d8c56d9c72822cc2c834e240ad1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f60d4d44e161c4c3e151ad73024a8228.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55eb4703dc394b53fef7d12030c470d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/914c9d4dc14490413e77f6262d2a7aa9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/323f4e181b418a66cc36d75e0f8da126.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81e743594b98ac2006344494dddfb345.png)
您最近一年使用:0次