如图,在四棱锥
中,底面ABCD是正方形,
底面ABCD,E,F分别是PC,AD中点.
(1)求证:
平面
;
(2)若
,PB与平面ABCD所成角为45°,求平面PFB与平面EFD夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/19/353e8b8f-92f4-43c1-877a-4bb44a5ed6f5.png?resizew=147)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/063510e3c1fb6a7ccc3b8e3e3c7d660e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e7d8c07bb0876c1e3eec161968f3d88.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4aca5534bce25acaeb7379deed8f8f.png)
23-24高二上·四川内江·阶段练习 查看更多[2]
更新时间:2023-12-11 20:30:06
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解答题-证明题
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解题方法
【推荐1】如图,在四棱锥
中,
底面ABCD,
,点E在棱PC上.
平面EBD,试确定点E的位置(图1),并说明理由;
(2)若底面ABCD是梯形,且
,点E是PC的中点(图2),证明
平面PAD;
(3)在(1)的条件下是否存在实数
,使三棱锥
体积为
,若存在、请求出具体值,若不存在,请说明理由;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a37d3fd7d81e4b177dee8f8e30d93159.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373f735f0f04d11f1951eaef1bb78b6a.png)
(2)若底面ABCD是梯形,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c909d7ad97c3f96fe54edca2cfe279.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c372d059202ec388960b125d4a87dc84.png)
(3)在(1)的条件下是否存在实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4773a26774ddc789ebf9e8da2e9ff0bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d599cb4a589f90b0205f24c2e1fa021e.png)
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【推荐2】如图,在四棱锥
中,
是等腰三角形,且
.四边形
是直角梯形,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2018/11/2/2066738188689408/null/STEM/1f42a6ad68474dff984f89d4c313d642.png?resizew=153)
(Ⅰ)求证:
平面
;
(Ⅱ)当平面
平面
时,求四棱锥
的体积;
(Ⅲ)请在图中所给的五个点
中找出两个点,使得这两点所在的直线与直线
垂直,并给出证明 .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02bd5cfe804460846423e77f72db10f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f409b28f7cb97726646e79709ad25190.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33c4c15c36855da900d07c03d12fd7c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/729d5cb74bb927aa549ce596a35b26b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c90a2e13488a5f4a2408718837fdabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b36a1938df65db2b68bf7595b97bafa2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac943d8c2eb91c0082ada87857d1ad0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfd880e197a74294650d90579563a7b8.png)
![](https://img.xkw.com/dksih/QBM/2018/11/2/2066738188689408/null/STEM/1f42a6ad68474dff984f89d4c313d642.png?resizew=153)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7178236b6fadcce9a5cae9ef80146f7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dda09fb28b8f1e165715cca61d64f9c1.png)
(Ⅱ)当平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/840798a31aba0783f96584e0ad7c0d2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02bd5cfe804460846423e77f72db10f.png)
(Ⅲ)请在图中所给的五个点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fd6e7723730c9b701d9b48a23e290dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
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解答题-证明题
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【推荐1】在四棱锥
中,底面
为直角梯形,
,
,
,
,
,
,
分别为
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/9e8ec421-a4c9-4aa4-bc57-ca3cc6e0e40d.png?resizew=166)
(1)求证:
.
(2)若
,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/ae1e04eeb4de72e5750dae77bcb6f88a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3bbe4cdd2c154bd9a8073b0d4cecb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b44f4120c94cb7176dc31fcac387b32e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/639bec6242a4b3f7bfb4b7033a67328c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62974d34de3a12418d6b700420afd1b2.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/9e8ec421-a4c9-4aa4-bc57-ca3cc6e0e40d.png?resizew=166)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf8c85a6fbe49bae5108176e2c65eaf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b7b9bf7332256ac478041957fa2a55a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3565370430d95207e5442ce3086ca04.png)
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【推荐2】如图,已知
是以
为斜边的等腰直角三角形,将
绕
转动到
位置,使得
,连接
,E、F分别是PA、CA的中点.
![](https://img.xkw.com/dksih/QBM/2022/5/14/2978811330174976/2979499290779648/STEM/9c988a408b2140d0b4f772fe273c58c7.png?resizew=214)
(1)证明:
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc8b9ac2fe2f52dafb676093dc7a23e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/2022/5/14/2978811330174976/2979499290779648/STEM/9c988a408b2140d0b4f772fe273c58c7.png?resizew=214)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab00e0cff0876c4183a47f1272cf9928.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b051f51b7d4ce0a3a6d0b7eb880a2fbf.png)
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