在
中,
,
,
分别为角
的对边,
,
.
(I)求
的值
(II)设
,求边长
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f44c181a2f6ae22d5d52b374768dc57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea25f36ed6250992455bdb773017ecca.png)
(I)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5201fc26d013f6fb889933c0e32f5c53.png)
(II)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/513587870824ff87b56f0ed927297869.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
更新时间:2019-04-18 15:29:53
|
相似题推荐
解答题-证明题
|
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(0.85)
名校
【推荐1】(1)试证明差角的余弦公式
:
;
(2)利用公式
推导:
①和角的余弦公式
,正弦公式
,正切公式
;
②倍角公式
,
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eee3f1c9130daa032e8cca82a339ad03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e6276ff5468f5aa9c6eaff479c26cc7.png)
(2)利用公式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eee3f1c9130daa032e8cca82a339ad03.png)
①和角的余弦公式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3af2b192544f360cdaca81ce533b5271.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9e93f28dbf8ba07ea1f8fa9eece0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecc799802966e0e59fcde18dc3140225.png)
②倍角公式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99d609b009b3be1329e305bd3802c4e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38d849c83c4696ebf978aa99ced19c88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57c9b03f86d4170819bf16623820d050.png)
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【推荐2】已知
,
.
(1)求
的值;
(2)若
,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75083d2a3f62c22971c6ef543e237420.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29bfdb5f50c0514b2b7cb83b2c29407b.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a975174b697129d6cc7bdaeaa9d5de71.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db538adbb2706f0b3b9dae38cc438f74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/423b2942c97548f9e6699d8d27209550.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
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解答题-问答题
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【推荐3】已知
,
,且角
,
分别位于第二、四象限,求
和
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a892dbcef7934d97016bb190d94e0bc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62e4fc7489911b0da3cc5d7194d9c6a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc3884b343d76a26b4b85b48987d7064.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbb006ea697b63a914eb487073f0abe1.png)
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解答题-问答题
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解题方法
【推荐1】在
中,角A,B,C所对的边分别为a,b,c.已知
,
,
.
(1)求角C的大小;
(2)求
的值;
(3)求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/120d8de1cbb60b60c44b9e19e54b98a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dd863a918ed0d67069ecbf95bf99ace.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/036b23c94e305faaa1283996edc5b30c.png)
(1)求角C的大小;
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c181f86de3c96a7ef7a1a04c3a438f.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/384b3984c623e73f30472da2a3f7ce5d.png)
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解答题-问答题
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【推荐2】在△ABC中,∠B=![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3033ce19fed91af7bcb5dfbfd4384c23.png)
(Ⅰ)求∠ADC的大小;
(Ⅱ)若AC=
,求△ABC的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3033ce19fed91af7bcb5dfbfd4384c23.png)
(Ⅰ)求∠ADC的大小;
(Ⅱ)若AC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38acfaa0f912c2598cc341ec98da8a08.png)
您最近一年使用:0次
解答题-问答题
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解题方法
【推荐1】锐角三角形ABC的三内角A、B、C所对边的长分别为
,设向量
,且
.
(1)求角B的大小;
(2)若
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52efd4cc33702767a6b3faf789d0953b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7da690264e9939a380260f4ee8ca3e8c.png)
(1)求角B的大小;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3c442579603164f3fc19458677d307.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd1810555c0c28fe352841322b85bbc6.png)
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解答题-问答题
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解题方法
【推荐2】钝角
面积为
,
,
,求
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca036d049f5205cf04cb1b9c5cd03f97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a47b376264d525c790ebad49a849c08.png)
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解答题-问答题
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【推荐3】已知
的三个内角
的对边分别为
,且
.
(1)求
;
(2)若
,求
得最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7738396445e1fb19a991f136b8087d5d.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fadd2e6f0aa16c2c466c904474ffc79c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dfa04ed69eb5e36931c076e0cf3f01e.png)
您最近一年使用:0次