名校
1 . 棱长为1的正方体
中,
为线段
上的动点,则下列结论正确的有
①三棱锥
的体积为定值; ②
;③
的最大值为
; ④
的最小值为2
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd694ad3a4733c7c84aaa7946aeea4de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b362fffbd6e0fef50ca51fc300d23d74.png)
①三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b414f9a354824ea7387512a2d84784f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2c36cf598f1fc28cc94c06dd96c2a94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d21fa7a95e0f1d7bf2c712c63bbeb65a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b12d93bd1130088b622602a6c21c9c2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4c318e1357d99848dcbb21a91318e63.png)
A.①② | B.①②③ | C.③④ | D.①②④ |
您最近一年使用:0次
解题方法
2 . 已知在正方体
中,点
是
中点,点
是
中点,若正方体
的内切球与直线
交于点
,且
,若点
是棱
上一个动点,则
的最小值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c0f067a2a348ceb24a408f82992eab8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e632c69a64b102daf0e20f2c0664d49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe2784c14959854fa245aeb169857013.png)
A.6 | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次