已知向量
是单位向量,
=(3,4),且
在
方向上的投影为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9db0f724f732c7a64d9a2212911d88f3.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/90ab17fd4247cdd710c363d5d3fbc5bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/969604545902c9a66549a4a44ec3a3c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af31ae78b8d67797eda6da26724eef9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9db0f724f732c7a64d9a2212911d88f3.png)
A.36 | B.21 | C.9 | D.6 |
更新时间:2019-07-04 08:30:31
|
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单选题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,
是边长为2的正三角形,直线
围成一个正三角形
,且
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76c42f73b6b4cd5308071e6bedb83049.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01bbe0491dc037390ef465b4deef4a20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37d6279b4170c8e4f36488a520ccc49d.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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【推荐2】点
为
所在平面内一点,
则
的形状为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aab016d071f2d3abbac6cdbd57612a19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
A.直角三角形 | B.等腰三角形 |
C.等腰直角三角形 | D.等边三角形 |
您最近一年使用:0次
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【推荐1】已知O是
的外心,外接圆半径为2,且满足
,若
在
上的投影向量为
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b92bb42b72c4125c6081ccc6732392e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/083a20abb668d4c26fe5039bd108b40a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89265cbe3abc6b966ce8967fead448b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22c55b0570e6d6f6938c62d6a56abb09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca902cd1857b0b95703521972a4214eb.png)
A.![]() | B.![]() | C.0 | D.2 |
您最近一年使用:0次
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解题方法
【推荐2】以C为钝角的
中,
,当角A最大时,
面积为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65a37ca33a5c05a4b2bad54a690e87cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
A.3 | B.6 | C.5 | D.8 |
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【推荐1】已知向量
,
的夹角为
,且
,
,则
( )
![](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/f1e5fa72f2878b476bc57f0df12d6555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70e310702748855c3edccd151aae0143.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eb4678685f70b7bb5fcf15df83942d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c67142c672f4ce0b994c1d7d444a2b47.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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【推荐2】已知向量
,
满足
,
,则
的最小值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c5562bd4d1b54424330cb6329cd79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0b3e82dce7de4981e890ea3e59b4821.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e2da925e2a02c2d1dec7e3ed294914c.png)
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A.![]() | B.![]() | C.8 | D.2 |
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