1 . 棱长为1的正方体
中,
分别是
的中点.
①
点在直线
上运动时,三棱锥
体积不变;
②
点在直线
上运动时,直线
始终与平面
平行;
③平面
平面
;
④三棱锥
的体积为
.
其中真命题的编号是_______________ .(写出所有正确命题的编号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b199a99e53d67ff4abf233930961a29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c526cb5d2242b7536f4620bd816bd2e.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ad99ef5e70de37345c708b758d545f.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27e66b12019cdf68327d34c90dff7c04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
③平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b376ab22caaf534d6655ac0ce2d8d84f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7977ab975efa6411cc17de39be70d9.png)
④三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db26bad88328665735fadf82f44d6730.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69ee3c61d2298e75fc4f1643f8ebc2e4.png)
其中真命题的编号是
您最近一年使用:0次
2021-01-10更新
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504次组卷
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2卷引用:海南省海南中学2021届高三第五次月考数学试题