20-21高一·全国·课后作业
解题方法
1 . 设
是正
边形
的中心,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b36681faaaba1e387e571a5d5b4f2be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d4de08623ef74998c3f8585d745ac6c.png)
您最近一年使用:0次
解题方法
2 . 已知
是线段
外一点,若
,
.
![](https://img.xkw.com/dksih/QBM/2021/7/1/2754738071633920/2780160458145792/STEM/bac1b25a-c8f5-4e9b-86a5-b2e03e3df44b.png?resizew=496)
(1)设点
是
的重心,证明:
;
(2)设点
、
是线段
的三等分点,
、
及
的重心依次为
、
、
,试用向量
、
表示
;
(3)如果在线段
上有若干个等分点,请你写出一个正确的结论?(不必证明)
说明:第(3)题将根据结论的一般性程度给予不同的评分.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/732e8008564ec12576ac60e498b28067.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e42eacb57037d08cf18946fe8e33bc6.png)
![](https://img.xkw.com/dksih/QBM/2021/7/1/2754738071633920/2780160458145792/STEM/bac1b25a-c8f5-4e9b-86a5-b2e03e3df44b.png?resizew=496)
(1)设点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fe95f656b98b53f71a9d72bf0c9a4b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d97d957da46828a1378c4e65da19c6ec.png)
(2)设点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3b9e816b14051f785aa5aae72b8eed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b332b48728db0c9332acf884ff7b8be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15536798ab47cadce6d4d80f542051f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c16dc4222a7f85cf7bdbb0cbc2a564f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/011ae6cb0cf49f6d3d19b485dc1cfc22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86fda993d38532293724009685288b72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a12119eba9da5c32568de5832ff04c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c94075193c11fe43f2396cff5a485054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/258310d763a29f2a88ae4284cf45dc07.png)
(3)如果在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
说明:第(3)题将根据结论的一般性程度给予不同的评分.
您最近一年使用:0次