1 . 求
的值时,可采用如下方法:令
,则
,两边同时平方,得
, 解得
(负值舍去),类比以上方法,可求得
的值等于( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c688fce38338cb229bafdb8c080596.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/200387a8fb9d5f2e622a1d84c47c5208.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/528d99251641d17d0433713fce220009.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28496b4b6c53e5504a0999a5f7b2f865.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93e48ad93f451e4fd2a2d9f0c30bb88a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54d87802aa3b69877370c63625f48ed4.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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2 . 某同学在一次研究性学习中发现,以下五个式子的值都等于同一个常数:
①
②![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1abed0bd12b3413ca1392595f5617b3.png)
③
④![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bc21026b55a98db4d2f7bf89f3093bf.png)
⑤![](https://staticzujuan.xkw.com/quesimg/Upload/formula/642e9a4223aedbb5a3c02d9dc883df8a.png)
(1)试从上述五个式子中选择一个,求出这个常数;
(2)根据(1)的计算结果,将该同学的发现推广为三角恒等式,并证明这个结论.
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ba95ab0173edb001f3ef85e98114e33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1abed0bd12b3413ca1392595f5617b3.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/211f1dca0a5b6e1f22c20434b74b84c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bc21026b55a98db4d2f7bf89f3093bf.png)
⑤
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/642e9a4223aedbb5a3c02d9dc883df8a.png)
(1)试从上述五个式子中选择一个,求出这个常数;
(2)根据(1)的计算结果,将该同学的发现推广为三角恒等式,并证明这个结论.
您最近一年使用:0次
2020-05-04更新
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44次组卷
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2卷引用:安徽省黄山市屯溪第一中学2019-2020学年高二下学期入学考试数学(文)试题