名校
解题方法
1 . 在正三棱柱
中,
,点
满足
,其中
,
.
(1)当
时,三棱锥
的体积为______ .
(2)当
时,存在点
,使得
平面
,则
的取值集合为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af0e44cb429eea46e7ee4320147192b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c03c651cf3b88c30981b2ed27d27043.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee72261f6901e62dfd0ffe547406544.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e2e01346f60857ff635bb766802e57.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2753dc1c83d54044b89e628a7eb247f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5aab98011d732d4094e4e881b0bd2bd6.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76819195cffab10d81638dd673f3af98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e16f65c3a318220c2f5baac171bbb61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4704cbf3d2de2f06a6ee29b3c252109.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/960966ead5bcb7fa70a3b941e018e45b.png)
您最近一年使用:0次
解题方法
2 . 如图,在
中,
,
,
,E为
的中点,
与
交于点F,G为
的中点.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfab72149ec6081c0295306d3d956a35.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd3ae3ea9d8354844aded187f4726543.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfab72149ec6081c0295306d3d956a35.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/27/7800c598-38c4-4470-899b-0591063f4d18.png?resizew=212)
您最近一年使用:0次
3 . 在△ABC中, ∠ABC=120°,BA=2,BC=3,D,E是线段AC的三等分点,则
的值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1cf047d01a1a252106ff8d0535415a5.png)
您最近一年使用:0次
4 . 在
中,
,
,D为AB边上的中点,则
等于______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eddf629bfb2d7b9daea6f2c1553360af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a69550d878381f6e8fb436e88638f070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b68d5fab76be5d73f357190f9d37f94a.png)
您最近一年使用:0次