名校
解题方法
1 . 如图,在三棱柱
中,平面
平面
,四边形
是正方形,点
,
分别是棱
,
的中点,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/18/8a2acfc5-4caf-4f4e-a525-06de8753f871.jpg?resizew=162)
(1)求证:
;
(2)求二面角
的余弦值;
(3)若点
在棱
上,且
,判断平面
与平面
是否平行,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61cdaadeae37736a1e6dd93fa1fe712f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/133760237c0ccf2d6a83786925b6d23c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/18/8a2acfc5-4caf-4f4e-a525-06de8753f871.jpg?resizew=162)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffeea0a84cdd67bd8bed95bc0f8ae364.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5d02ab4d51f92d437057fd7ff9c1c1.png)
(3)若点
![](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/61506e84751cbb8791a10630c62b57cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41104641f3e2260d00aeadf8fb8a078a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
您最近一年使用:0次
2020-05-11更新
|
635次组卷
|
2卷引用:2020届北京市朝阳区高三第一次模拟考试数学试题
2010·北京朝阳·二模
解题方法
2 . 如图,在四棱锥
中,底面
是正方形,其他四个侧面都是等边三角形,
与
的交点为O.
(Ⅰ)求证:
平面
;
(Ⅱ)已知
为侧棱
上一个动点. 试问对于
上任意一点
,平面
与平面
是否垂直?若垂直,请加以证明;若不垂直,请说明理由.
![](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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d30637da200a07672ae231b4c5c09cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(Ⅱ)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cc6f6dfdbe7d39891c35f67e1a95c7f.png)
![](https://img.xkw.com/dksih/QBM/2010/5/10/1569723786174464/1569723791433728/STEM/d8b5dadf27624f869fe12c9235ec0d2e.png?resizew=247)
您最近一年使用:0次