1 . 在空间直角坐标系中,向量
,则
的最大值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f96cf2538b30e34444e06eb54beeef79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/854e16eb319ee454088f5b527cf6c4d5.png)
您最近一年使用:0次
2 . 如图,在长方体
中,
为棱
的中点,点
是侧面
上的动点,满足
,给出下列四个结论:
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/6/b6c99aeb-145d-4106-9230-1f577e7c4384.png?resizew=183)
①动点
的轨迹是一段圆弧;
②动点
的轨迹长度为
;
③动点
的轨迹与线段
有且只有一个公共点;
④三棱锥
的体积的最大值为
.
其中所有正确结论的序号是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c338c277213e4176c9b67e0b9f8be9fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c52091eb745de866044477641a7c55f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c05058f5a119f7b10644bab23e8f3533.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/6/b6c99aeb-145d-4106-9230-1f577e7c4384.png?resizew=183)
①动点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
②动点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1a63ab608517bb10aa036783dfb51f.png)
③动点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
④三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b03ab10cdcb79af60acfb52b85f910d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82c779d5364c9231b1dfab30545ad045.png)
其中所有正确结论的序号是
您最近一年使用:0次