2024高三·全国·专题练习
解题方法
1 . 正三棱柱
中,试确定侧面
及
上对角线
垂直于
的条件.(写出一个即可)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
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2 . 如图甲,E是边长等于2的正方形的边CD的中点,以AE、BE为折痕将△ADE与△BCE折起,使D,C重合(仍记为D),如图乙.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/fa404fb9-856e-417c-9dee-415fd29d5324.png?resizew=392)
(1)探索:折叠形成的几何体中直线DE的几何性质(写出一条即可,不含DE⊥DA,DE⊥DB,说明理由);
(2)求二面角D-BE-A的余弦值
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/fa404fb9-856e-417c-9dee-415fd29d5324.png?resizew=392)
(1)探索:折叠形成的几何体中直线DE的几何性质(写出一条即可,不含DE⊥DA,DE⊥DB,说明理由);
(2)求二面角D-BE-A的余弦值
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2020-06-21更新
|
777次组卷
|
2卷引用:西南名校联盟2020届“3+3+3”高考备考诊断性联考卷(三)数学(理科)试题
3 . 如图,在棱长均为
的三棱柱
中,点
在平面
内的射影
为
与
的交点,
、
分别为
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/6/4dcf618a-1664-4df2-88f8-f81efd99422b.png?resizew=249)
(1)求证:四边形
为正方形;
(2)求直线
与平面
所成角的正弦值;
(3)在线段
上是否存在一点
,使得直线
与平面
没有公共点?若存在求出
的值.(该问写出结论即可)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/6/4dcf618a-1664-4df2-88f8-f81efd99422b.png?resizew=249)
(1)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e53b212640dadf751ef7f65a78a209.png)
(3)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e21468a972babcefc0028f2bd1f56336.png)
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