如图,在直三棱柱
中,
,
,点D为
的中点,点E为
的中点,点F为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/31/1d812c26-b072-4a44-a595-84be2d697ae6.png?resizew=185)
(1)求证:
平面
;
(2)求平面
与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/002c709e9fee8d477bddfe595cc760f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/822ba132ca9dd0d4a050659aef3c9b26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/31/1d812c26-b072-4a44-a595-84be2d697ae6.png?resizew=185)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d008e2db7380fa8b41fb604e41ef053f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e367b683581c7cbe018078168f69efc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0186d11008c7d66c85ed0d8d2e568908.png)
更新时间:2024-01-16 11:47:12
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图:已知四棱柱
的底面是菱形,该菱形的边长为1,
,
平面
.
![](https://img.xkw.com/dksih/QBM/2016/1/15/1572437525970944/1572437532049408/STEM/207a093cce4a45869e245e942f78e609.png?resizew=244)
(1)设菱形
的对角线的交点为
,求证:
//平面
;
(2)若四棱柱的体积
,求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26d4e574c9d139615d991a168cfbf63b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2016/1/15/1572437525970944/1572437532049408/STEM/207a093cce4a45869e245e942f78e609.png?resizew=244)
(1)设菱形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3dc526324e78e4d9226d1b537f27845a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4508dc6d9c91157836be679c0543cac.png)
(2)若四棱柱的体积
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52a00b7a5a13dcd4d0d90809bf8880f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53e97fcdcfd6183b976a61ef3222c607.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4508dc6d9c91157836be679c0543cac.png)
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名校
【推荐2】如图是某直三棱柱(侧棱与底面垂直的三棱柱)被削去上底后的直观图与三视图中的侧视图、俯视图,在直观图中,
是
的中点,侧视图是直角梯形,俯视图是等腰直角三角形,有关数据如图所示.
![](https://img.xkw.com/dksih/QBM/2017/8/19/1755295172976640/1756094042406912/STEM/3dd5ed8311b343bd8c1e2a17dab87c36.png?resizew=183)
(1)求出该几何体的体积;
(2)若
是
的中点,求证:
平面
;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/2017/8/19/1755295172976640/1756094042406912/STEM/3dd5ed8311b343bd8c1e2a17dab87c36.png?resizew=183)
(1)求出该几何体的体积;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83b074a2f55d46350f0628ae6121c558.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d3f4156473d86ce03ca64bd17f9dad6.png)
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【推荐3】如图,在四棱锥
中,
平面
∥
,
,E为
的中点,F,M分别在
和
上,且
.
![](https://img.xkw.com/dksih/QBM/2021/11/12/2849589160329216/2849960927330304/STEM/f838c585cc1c424ea5d2253a38212896.png?resizew=242)
(1)若N在
上,且
∥平面
,求证:
∥平面
;
(2)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/e0f092cae19e108485e19c59f7bd1fec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52a923784f083b7f4777891afe06b44e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6051ca1bcca226b0cee6d8cdc4cca03d.png)
![](https://img.xkw.com/dksih/QBM/2021/11/12/2849589160329216/2849960927330304/STEM/f838c585cc1c424ea5d2253a38212896.png?resizew=242)
(1)若N在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3533837e3d08c461dea031a44e5424d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/242657c0f6a356f2cbdfc23cfff7d3e4.png)
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解答题-证明题
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【推荐1】如图所示,四棱锥S﹣ABCD中,四边形ABCD为平行四边形,BA⊥AC,SA⊥AD,SC⊥CD.
(Ⅰ)求证:AC⊥SB;
(Ⅱ)若AB=AC=SA=3,E为线段BC的中点,F为线段SB上靠近B的三等分点,求直线SC与平面AEF所成角的正弦值.
(Ⅰ)求证:AC⊥SB;
(Ⅱ)若AB=AC=SA=3,E为线段BC的中点,F为线段SB上靠近B的三等分点,求直线SC与平面AEF所成角的正弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/0b11ca89-432b-41a5-be60-ef78eef71976.png?resizew=191)
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解题方法
【推荐2】如图,在三棱锥
中,
是边长为4的正三角形,平面
平面
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/361d35d0-161d-42c6-ab20-6271baafa0a2.png?resizew=157)
(1)证明:
;
(2)求二面角
的余弦值;
(3)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41e5db1d2fd912f77923e4c120a7dc19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78307cd417504554a4e2276fe24d1162.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55ca6072b3a2aac406a2b60bb7e01cde.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/361d35d0-161d-42c6-ab20-6271baafa0a2.png?resizew=157)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90fa715d27ae43ec1e157226bc9dea54.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0262d3168bd3296cc63c4d78965cbb2c.png)
(3)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a81b7c9e813895fc25d32a52e15c5f4.png)
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【推荐1】如图,在三棱柱
中,侧面
是菱形,且
,侧面
是边长为
的正方形,侧面
侧面
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/7/f1f3f828-0bfa-44ab-a555-a38d18fbfc44.png?resizew=204)
(1)求证:
平面
;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd57614136e2fc269f698a9c3904e31f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f96c673a2381f118ea2d3efc0bca1f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3e34cc1159ab9198480cd0b585620d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/7/f1f3f828-0bfa-44ab-a555-a38d18fbfc44.png?resizew=204)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc75a6b2fef29e6325349803099a1cc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176b7beb3ee58b075801d6d7f6af1a4f.png)
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【推荐2】如图,在四棱锥
中,
是以
为斜边的等腰直角三角形,
,
,
,
,
为
上一点.
![](https://img.xkw.com/dksih/QBM/2020/12/24/2621261692698624/2624813725278208/STEM/11a76621-9e58-44d8-b875-ab452ba3df20.png)
(1)若
为
的中点,证明:
平面
;
(2)若直线
与底面
所成角的正弦值为
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02bd5cfe804460846423e77f72db10f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9026fbd7897d459b4d559a4b99f2e41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c58bafdd3bb54ba3491b49ab60b172f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed4e4b72607f34923d90890c25475449.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae774b98a2a4897967c89095fccb7c78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2783c8a27da6f95a077d9e7f8e47d386.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/365822bd3945e6a3e871ca979c84cc12.png)
![](https://img.xkw.com/dksih/QBM/2020/12/24/2621261692698624/2624813725278208/STEM/11a76621-9e58-44d8-b875-ab452ba3df20.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/365822bd3945e6a3e871ca979c84cc12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0138efef1aa28c5b2b1063426ad87a4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4da035673ef0edcfae6b72fb5e5ba34a.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6b41d4070854edfaa24071137b314cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8067cbba862cec3ae86b5e14878c5bc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/873495e2ad831527b8c6559c0641a7f2.png)
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