23-24高一下·全国·课前预习
1 . 两个向量共线的坐标表示
(1)向量
共线的坐标表示
设
,则
⇔______________ .
(2)向量共线的坐标表示的推导
①设
,则
⇔
(λ∈R).
上式若用坐标表示,可写为
⇔______________ ,
即
⇔
⇔______________ .
②设
时,
⇔_______________ .
综上①②,向量共线的坐标表示为
⇔______________ .
(1)向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8e8b95a61af300412fc65f846089028.png)
设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38c119bbc0aa53cac8b90bfd2ffe3523.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91b958a367fa2f08b6202a5a6ebf5e9f.png)
(2)向量共线的坐标表示的推导
①设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d921460bbbee3fdcc60ae2db629ed22b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91b958a367fa2f08b6202a5a6ebf5e9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11aeda90bd9777fda412249a37fc7a08.png)
上式若用坐标表示,可写为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91b958a367fa2f08b6202a5a6ebf5e9f.png)
即
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91b958a367fa2f08b6202a5a6ebf5e9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ce86b3c1bdca8583e8371161bdd0c70.png)
②设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e9eda8783044fcca1c0b40c308773c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91b958a367fa2f08b6202a5a6ebf5e9f.png)
综上①②,向量共线的坐标表示为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91b958a367fa2f08b6202a5a6ebf5e9f.png)
您最近一年使用:0次