已知
,
,且
与
的夹角为
.
(1)求
;
(2)若
,求实数
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8faf351b569991fbdb8d8d30c72e72b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fbcc0fa4b480c43e9a66273898c9a60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/969604545902c9a66549a4a44ec3a3c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90ab17fd4247cdd710c363d5d3fbc5bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/231b861d6d1f1d0b9f52b041cb40eb62.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d5fa3de8948f50d1ce79822ff88aa91.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f69c0d86b4b56dc6508d1ece909558f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
更新时间:2019-01-28 22:16:04
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐2】已知
,
,
均为锐角,且
.
(1)求
的值;
(2)若
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afb2a6ac6bb1cb11445577dd97e0fa30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68cdbf875cf2202e08fa65590d9c9908.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e288596fa3811dd2c17bded60e82e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ed07e99386d4031c10569f797187ffb.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc3884b343d76a26b4b85b48987d7064.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9bc052a11cf1a01445992672dde2836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eacde1c42151734fdc60f3001b590de.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐3】已知平行四边形ABCD中,向量
,
,
,
,
.
(1)求
的大小;
(2)求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7b9d8a08fc52c31cc1a7f527d18b55c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/184359fe3cadc363cf4ebe586c2b3db4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/145a7e8f352fab613b773dc6639b508b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87a4fe23b799a0777b2faebd77dd05bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5554c2575a9759d321ab4d119b921bbf.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cc23a04cdac6439ea170e799f1c1df5.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】已知等边
的边长为2,点D是
边上的中点,点E是
边上靠近点A的三等分点.
(1)设
,请直接写出
的最小值及对应的实数
;
(2)设
与
交于点O,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/995ec593baa4ef50b6d87c78380953d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40a28142ca1f7f26e09abced156daba1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef3004955f86556fa23f1d3ac9b37651.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】如图所示,在边长为2的等边△ABC中,点M,N分别在边AC,AB上,且M为边AC的中点,设
,
.
![](https://img.xkw.com/dksih/QBM/2022/5/11/2977278207942656/2978403252985856/STEM/27180af1-ff82-4bab-9b6f-c15729d27504.png?resizew=151)
(1)若
,用
,
表示
;
(2)求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfca12290a98993f84d7ee4b8caaa9d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf7ae4dd35c90a6da3c7f604ea0861af.png)
![](https://img.xkw.com/dksih/QBM/2022/5/11/2977278207942656/2978403252985856/STEM/27180af1-ff82-4bab-9b6f-c15729d27504.png?resizew=151)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6abd9c737f9dee785a13d23b58bb9a2c.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/fb93bee3008094ff1faf0dc99eba9318.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8155cdb33ab3817286369a8cf3b1cbcf.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,在直角梯形
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/6381d10f-944b-40ba-9adc-b4bb7d1c33f2.png?resizew=197)
(1)若
,求
的值;
(2)若
,求
与
的夹角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d85c19747eb51dcab764f6c6d2e8db02.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/6381d10f-944b-40ba-9adc-b4bb7d1c33f2.png?resizew=197)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1064febe4e68fa2a5dccc0e7e6d75f48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3cf0f585938ede9eca890a6eb326d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be64d59ac6538a0f4d79fb825e082081.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed2cf03ac7a1b0aba75daa3b9f9b5768.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】已知
,
,
在同一平面内,且
.
(1)若
,且
,求
;
(2)若
,且
,求
与
的夹角的余弦值.
![](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/d366d8fbb7258ee051f49977441e14a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6569e50f43b3d8645652ecc13b62066e.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba075a5bd4cb612a408544f824732aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b580b1e474eb43d7e7e2634ece223036.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb573cc0f30d5c32cdad1510793f0e7b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/939955fcd19578dc8f37415c60b187ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b91edd05cfbe13e45ce64805634a63f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c94075193c11fe43f2396cff5a485054.png)
您最近一年使用:0次