如图,
是边长为3的正方形,
平面
,
,
,
与平面
所成角为
.
(1)求证:
平面
.
(2)求二面角
的余弦值.
(3)设点
是线段
上的一个动点,试确定点
的位置,使得
平面
,并证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b059af31eed9d4ec27f9aad55ae41df6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c5624c7941eb3cca11d8efbe76d9af5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/074c228ffc7b1e306f8410afe7bc4b5c.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f717b7d4d0978eec7330afec554c078.png)
(3)设点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae0d2ea2af3f0ab189c4694eeb52ce43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/1f07df0e-7ce3-4f84-8099-497997972903.png?resizew=185)
更新时间:2020-02-07 16:45:53
|
相似题推荐
解答题-问答题
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适中
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名校
【推荐1】如图,侧棱与底面垂直的四棱柱ABCD,A1B1C1D1的底面是梯形,AB∥CD,AB⊥AD,AA1=4,DC=2AB,AB=AD=3,点M在棱A1B1上,且A1M=
A1B1.已知点E是直线CD上的一点,AM∥平面BC1E.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/90df94ae-e3e0-444c-a300-a01939b61fc7.png?resizew=160)
(1)试确定点E的位置,并说明理由;
(2)求三棱锥M-BC1E的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/90df94ae-e3e0-444c-a300-a01939b61fc7.png?resizew=160)
(1)试确定点E的位置,并说明理由;
(2)求三棱锥M-BC1E的体积.
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解答题-证明题
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【推荐2】在如图所示的几何体中,四边形CDEF为正方形,四边形ABCD为等腰梯形,AB∥CD,AC=
,AB=2BC=2,AC⊥FB.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/31/4622d884-c9f0-46e1-8f06-752d8008a738.png?resizew=177)
(1)求证:AC⊥平面FBC;
(2)求四面体FBCD的体积;
(3)线段AC上是否存在点M,使EA∥平面FDM?若存在,请说明其位置,并加以证明;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/31/4622d884-c9f0-46e1-8f06-752d8008a738.png?resizew=177)
(1)求证:AC⊥平面FBC;
(2)求四面体FBCD的体积;
(3)线段AC上是否存在点M,使EA∥平面FDM?若存在,请说明其位置,并加以证明;若不存在,请说明理由.
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解题方法
【推荐1】如图,在四棱锥
中,底面
为直角梯形,
∥![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a1cf657792edb2da8c7c896d7320c8d.png)
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/4/78ef4059-62d8-42c0-bbcd-69119d3078ae.png?resizew=170)
(1)证明:平面
平面
;
(2)求平面
与平面
所成锐二面角的余弦值.
![](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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a1cf657792edb2da8c7c896d7320c8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1978a295d286af6fe42538cd3dbb88a9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/4/78ef4059-62d8-42c0-bbcd-69119d3078ae.png?resizew=170)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
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解题方法
【推荐2】如图,三棱柱
的侧面
为菱形,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/18/bcba4bb8-bbeb-4b21-a30f-0247c00f3acc.png?resizew=210)
(1)证明:
;
(2)若
,求四棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a217610f63501471f0fa3f70c52283e9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/18/bcba4bb8-bbeb-4b21-a30f-0247c00f3acc.png?resizew=210)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb81a917e1183890a82885b350b63f14.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9d45cccf514b364d4ea1c3554c929f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2d0727de4c16b53b4bb6ab370afde6c.png)
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【推荐3】如图,在平行四边形
中,
.以
为折痕将
折起,使点
到达点
的位置,且二面角
的大小为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/11/7d606977-0fce-4147-ab14-ed1eac6a180e.png?resizew=195)
(1)求
;
(2)设
为
上一点,求直线
与平面
所成角的正弦值的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0760712e3e2ea02b755b751e760d0c55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f17c2222ccbb93af7bc2e8c307c92ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dddb32a7a5c157fdf8aa049b2d665b4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f0ac3005d5ecd6d4cea0ce99a47ef3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/11/7d606977-0fce-4147-ab14-ed1eac6a180e.png?resizew=195)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
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【推荐1】如图,在四棱锥
中,底面
是边长为
的菱形,
,侧面
为等边三角形.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/39769caa-db2f-4cb1-ad3a-b28a3115e6af.png?resizew=186)
(1)求证:
;
(2)若
的大小为
,求
的正弦值.
![](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/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/39769caa-db2f-4cb1-ad3a-b28a3115e6af.png?resizew=186)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdfa54114f04a75b8c96165b3718ed7f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c911b404bbb8f8d5f1470585fa31ad97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
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名校
解题方法
【推荐2】如图,在斜四棱柱
中,四边形
为平行四边形,
平面
为
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/3/1b05ab49-70b6-4109-8b17-ee73f400ca17.png?resizew=198)
(1)证明:平面
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/949a59c57f028dfbfd7d6605a6bb3722.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f611bd6db02fe362bc9682359378c85d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/3/1b05ab49-70b6-4109-8b17-ee73f400ca17.png?resizew=198)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/351464da41a2bd5d431d9c427382f1f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f4525d2a5cfdd4c82f62c28177d6cf9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f73e874947bd843187ead9cd47395ba.png)
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