1 . 如图,四棱锥
中,底面
是边长为2的菱形,
,已知
为棱
的中点,
在底面的投影
为线段
的中点,
是棱
上一点.
(1)若
,求证:
平面
;
(2)若
,确定点
的位置,并求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff5a86745bfe1dfe7bc2683811210330.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.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/2024/3/15/3c1cdb7d-5f31-4e1d-93d6-39a1f6a08b6b.png?resizew=218)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd77b37a624d551fb77afc62b98204f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28f79db7c270b6ff9fb0a538ee201cfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9af29254fe60a392c249c5791279e9c8.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd3097f5b558b253b7076b2499c39ee4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ce9b8c1c0365b5a1cd8d4a01c271df.png)
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名校
2 . 如图,在四棱锥
中,
,
,
,△MAD为等边三角形,平面
平面ABCD,点N在棱MD上,直线
平面ACN.
.
(2)设二面角
的平面角为
,直线CN与平面ABCD所成的角为
,若
的取值范围是
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4117625867a74cd022584500c76deca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bf10d92f20501e19d25f6f4159aab89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7ee81b6066188abee9d167b6c7f3f71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e05d8681a679bd31922e62480f69d55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/451604e8cbe0706585d9cd2c76db4b90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f74c46a80f7540470b5e171e2e17d3bf.png)
(2)设二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/698335f4880c7a298f4898c83b6562bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cc9750c313ee972124cb62c4a6fb7ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97de9d1a07d32cae0e86d73482477da5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43660b1543b3a2b46185f7629d28a963.png)
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2023-06-30更新
|
2859次组卷
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8卷引用:陕西省西安市莲湖区2022-2023学年高一下学期期末数学试题
3 . 某工厂欲加工一件艺术品,需要用到三棱锥形状的坯材,工人将如图所示的长方
材料切割成三棱锥
.
![](https://img.xkw.com/dksih/QBM/2016/7/5/1572883895296000/1572883900850176/STEM/1450807eaf854de487145d59f60ef73f.png)
(Ⅰ)若点
分别是棱
的中点,点
是
上的任意一点,求证:
;
(Ⅱ)已知原长方体材料中,
,
,
,根据艺术品加工需要,工程师必须求出该三棱锥的高;
(i)甲工程师先求出
所在直线与平面
所成的角
,再根据公式
求出三棱锥
的高
.请你根据甲工程师的思路,求该三棱锥的高;
(ii)乙工程师设计了一个求三棱锥的高度的程序,其框图如右图所示,则运行该程序时乙工程师应输入的
的值是多少?(请直接写出
的值,不要求写出演算或推证的过程)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d6e2c5a15ee96de5510c38f68069f56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07f08e3fae189d0de5cb992e4007fca9.png)
![](https://img.xkw.com/dksih/QBM/2016/7/5/1572883895296000/1572883900850176/STEM/1450807eaf854de487145d59f60ef73f.png)
(Ⅰ)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de7878423936bda0d3fe504c4cd81bfa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93a9d8b29c7c25bf005c8fa849212eb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fb949f2a7ee89566c5c02b75043f6a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dffc708961cf03f696473e68986b7dd1.png)
(Ⅱ)已知原长方体材料中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827064e34563a7f678020ee1fa9b1683.png)
(i)甲工程师先求出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/826c728050e3378921442ace20269ef6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4734735213b599a9915e1ed91a5d8ce4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26ab55147ca5c0f958af43b0637ee31b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c5f8d58ee8a1fca928c91bc384d014a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07f08e3fae189d0de5cb992e4007fca9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eabd5f3a86afe49dcd70571e2b96cfd.png)
(ii)乙工程师设计了一个求三棱锥的高度的程序,其框图如右图所示,则运行该程序时乙工程师应输入的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://img.xkw.com/dksih/QBM/2016/7/5/1572883895296000/1572883900850176/STEM/1d4dbe7a351a4097b41c15db6f6744d6.png)
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