题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034525-99623.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034525-45249.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034525-45249.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-75611.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-79417.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-79417.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-46721.png)
(1)求cos(
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034525-45249.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-79417.png)
(2)若0<
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034525-45249.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-36133.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-36133.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-79417.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-79417.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034527-47733.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034525-45249.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034527-44700.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034527-76071.png)
解析
试题分析:(1)根据向量的坐标运算得
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034527-88291.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034526-46721.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034528-28228.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034528-69316.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034528-62102.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034528-81300.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034525-45249.png)
(1)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034529-98280.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034529-84100.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034529-18333.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034529-55670.png)
即
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034530-87191.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034530-75520.png)
(2)∵
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034530-60809.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034530-24172.png)
∵
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034531-52396.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034531-87926.png)
∵
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034531-92336.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034531-82662.png)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034532-62258.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034532-10339.png)
核心考点
试题【已知向量 =(cos,sin),=(cos,sin),。(1)求cos(-)的值; (2)若0<<,-<<0,且sin=-,求sin的值.】;主要考察你对平面向量数量积的意义等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034520-69814.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034520-20937.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034520-47735.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034520-84308.png)
A.![]() | B.![]() | C.4 | D.12 |
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034513-47780.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034513-84041.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034506-81144.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034507-54246.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034507-27697.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034507-60354.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034459-47786.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034459-20471.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034459-80022.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034500-87820.png)
(1)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034500-21118.png)
(2)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034459-80022.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034500-24231.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034450-67067.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034451-84219.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034451-67508.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034451-34682.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034451-14376.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034451-23538.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034452-43215.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034452-74553.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034452-84200.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034452-53184.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034452-65706.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034452-99941.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104034452-54298.png)
A.8 | B.6 | C.4 | D.0 |
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