名校
解题方法
1 . 在平面直角坐标系中,已知点
,
,
.
(1)若三点
共线,求实数
的值;
(2)若
是锐角三角形,求实数
取值范围;
(3)是否存在实数
,使得
在
上的投影向量是
?若存在,请求出实数
的值,若不存在请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4f1f2b3e349a9be5fb156ae31525b9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e1fa617863e37a37908aba227fce3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9316f8a58f503d0ea3879b8be30eaae.png)
(1)若三点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(3)是否存在实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abcb5d89b04570ceda2c29e11cb27a57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af5f1b06a56fc382feed28e01f1ad102.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb06a3f2fa360df918aa916b32b0168f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
您最近一年使用:0次