(1)叙述并证明余弦定理;
(2)在
中,内角
所对的边分别为
,证明:
.
(2)在
![](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/e63471f592531e46277365ed319e2acc.png)
更新时间:2021-08-16 08:15:59
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【推荐1】在
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【推荐2】在
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【推荐1】已知
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