名校
解题方法
1 . 已知四棱锥
的底面
为平行四边形,
平面
,
,
,
,
,
分别为
中点,过
作平面
分别与线段
相交于点
.
(1)在图中作出平面
,使平面
// 平面
,并指出P、Q的位置(不要求证明);
(2)若
,求二面角
的平面角大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fb2e071d4e01107dcf7d95cbb86b415.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bc2e11ba41dd6be2c30615229068a7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4aca5534bce25acaeb7379deed8f8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6e0b64d25ddd18454f88e40c45d7d8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6670479a0083dd2dfd5ad55b47b1ab6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d62718bb9eb6df7abeb6dcd9805b0b7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/389bc3f29c058067e06e0d0d2be399da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1b37e6adf86f4e108cd5bae7d9d4941.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5b1b15a4605fce993cb13aefbf40360.png)
(1)在图中作出平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/389bc3f29c058067e06e0d0d2be399da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/389bc3f29c058067e06e0d0d2be399da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d923a338dd2d2e29336b42574d38448.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43e51b296d70944119042e560a7837db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db16410eb75958a577d7aa8a47fb88ad.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/17/04db700d-e35c-48b5-ab72-289e41e8b183.png?resizew=170)
您最近一年使用:0次
解题方法
2 . 已知四棱锥
中,底面为矩形,
底面
,
,
为
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/9/19a23b04-4568-48ba-8167-b0579df84fef.png?resizew=250)
(1)在图中作出平面
与
的交点
,并指出点
所在位置(不要求给出理由);
(2)在线段
上是否存在一点
,使得直线
与平面
所成角的正弦值为
,若存在,请说明点
的位置;若不存在,请说明理由;
(3)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd893c4964b7f1ef69f0563d74c76d0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbbb48c435c1ea5452cd9c9dd05e53ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/9/19a23b04-4568-48ba-8167-b0579df84fef.png?resizew=250)
(1)在图中作出平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ddb7c2ca1b6bee86cb24fed02e40da2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ddb7c2ca1b6bee86cb24fed02e40da2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d83fb9ac8a18e78a4c56da79514b5ccb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f36a631b790fbfabb6a41f44c7445126.png)
您最近一年使用:0次