1 . 设向量
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdc7e3e1938afb45e3c1b6453476e712.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fff57f443e8d2ee0c1ccd60c7c018fee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
您最近一年使用:0次
解题方法
2 . 设向量
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac715babfb5110cfe3b1adfa5d71a7d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70facc9bc02af0867d248407bd317c05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
您最近一年使用:0次