如图,四棱锥
内,
平面
,四边形
为正方形,
,
.过
的直线
交平面
于正方形
内的点
,且满足平面
平面
.
的轨迹长度;
(2)当二面角
的余弦值为
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45fbffb9e2c7fa7c5006cde8da0cabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbd051fedb6691e2183e658f1fe487ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392469b357b12b998528499929366c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a03203dd5ac79dd8c6707e4340773359.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
(2)当二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a1a4b8e6a3514ac93b69042d1f9553b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7294f5ae2a24ff42e84cd9773b2a7287.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d5c3c0ab9b7ba915604ed7e4e19254f.png)
23-24高二上·江西景德镇·期中 查看更多[3]
江西省景德镇市昌江区景德镇一中2023-2024学年高二上学期11月期中考试数学试题(已下线)专题01 空间向量与立体几何(4)(已下线)安徽省天域全国名校协作体2024届高三下学期联考(二模)数学试题变式题16-19
更新时间:2023-11-13 23:05:23
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相似题推荐
解答题-证明题
|
较难
(0.4)
【推荐1】如图,在四棱锥
中,平面
平面
,四边形
是直角梯形,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/85c4ab2e-8099-49d2-8a6c-cf2a505f8783.png?resizew=148)
(1)求证:
;
(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/27a9f169ceab716fa1f7c1d959565398.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3154f66b584a0e3b775f322b3d8c67f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f650016a872bb6c06ce30d9eac616d58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/85c4ab2e-8099-49d2-8a6c-cf2a505f8783.png?resizew=148)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/108ed83f0d6595284e1f9d27c06150e9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1069d514c3c32aeabd274475ee209ed6.png)
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【推荐2】如图1,在
中,
,
分别为
,
的中点,
为
的中点,
,
.将
沿
折起到
的位置,使得平面
平面
,如图2.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/8ef76929-4cf4-4d0a-80dc-7c3ef3754c48.png?resizew=354)
(1)求证:
.
(2)求直线
和平面
所成角的正弦值.
(3)线段
上是否存在点
,使得直线
和
所成角的余弦值为
?若存在,求出
的值;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0117046e7a37bebe0c7b987a00d2bcb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa2a83fed9bf4cb09d84a980452e346.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7b3e7c7845a0ec3cbac709fda131764.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65c42bce098904b241986bb91c65ab33.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/8ef76929-4cf4-4d0a-80dc-7c3ef3754c48.png?resizew=354)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e51c4114e94bceb198403c1858b9682.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(3)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a261474cc7607d31a6324cb4df9c8896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c741af321a8ddaf387fa661f3920ad84.png)
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解题方法
【推荐3】如图,在直三棱柱
中,
,
.
![](https://img.xkw.com/dksih/QBM/2022/9/12/3064881370423296/3066134020325376/STEM/aae63029e9094b7bbe50b06144b84441.png?resizew=240)
(1)设平面
与平面ABC的交线为l,判断l与AC的位置关系,并证明;
(2)求证:
;
(3)若
与平面
所成的角为30°,求三棱锥
内切球的表面积S.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1240a927e5540d2dce76ba019f6cf82.png)
![](https://img.xkw.com/dksih/QBM/2022/9/12/3064881370423296/3066134020325376/STEM/aae63029e9094b7bbe50b06144b84441.png?resizew=240)
(1)设平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9539f8fb13345b449274b67bbda995db.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e862713d078c4f06ec1f15ccd6f5a1f7.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d38593653bedb845ecfa820806a29a1e.png)
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解题方法
【推荐1】如图所示,在斜三棱柱
中,底面是等腰三角形,
,
是
的中点,侧面
底面
.
;
(2)过侧面
的对角线
的平面交侧棱
于点
,若
,求证:截面
侧面
;
(3)若截面
平面
,
成立吗?请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a9ad711b25c36dae0c2a2cedff9954.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50d9bdbbdfabc737323692c796e41930.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38c0e83c03e0864ff00b26af15ff7056.png)
(2)过侧面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bea287616019d94c51c7362627a38eba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99d020167b334dfda0dce811c519d323.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
(3)若截面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99d020167b334dfda0dce811c519d323.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bea287616019d94c51c7362627a38eba.png)
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【推荐2】如图,在多面体
中,平面
平面
.四边形
为正方形,四边形
为梯形,且
,
是边长为1的等边三角形,
为线段
三等分点(靠近点
),
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/7678c3e5-bc5e-4acc-ba99-f66e71160243.png?resizew=237)
(1)求证:
;
(2)求直线
与平面
所成角的正弦值;
(3)线段
上是否存在点
,使得直线
平面
?若存在,求
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/866a6cb2f0ef738f62fa9fa372c0819b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecc1cb55a57dde481f8dd07ab150676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d16a4959a99193a52d6fa8648cb2eb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00a28be4d5a16cf245f6fa7c4088fee4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da9dcf6c319174c9ea2b1ceaed1649a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f02795ff1af51fb0672800ceb02e7893.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/7678c3e5-bc5e-4acc-ba99-f66e71160243.png?resizew=237)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc553932ce81b2c940b34b28d80c8146.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/907d5147cea4c9ce855074864fe54506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
(3)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe9eeee83b4b7c6ceac7828ff534ce15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58a20ea69475dcf57a5ff18c13eceaaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ff65109fbe7d397800f32b47cf38a22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a459b45690bb921bbae09065b3df9f1f.png)
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【推荐3】如图,点C在直径为AB的半圆O上,CD垂直于半圆O所在平面,平面ADE⊥平面ACD,且CD∥BE.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/eef206de-b81d-46fe-a5f9-088adbb04306.png?resizew=204)
(1)证明:CD=BE;
(2)若AC=1,AB=
,∠ADC=45°,求四棱锥A -BCDE的内切球的半径.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/eef206de-b81d-46fe-a5f9-088adbb04306.png?resizew=204)
(1)证明:CD=BE;
(2)若AC=1,AB=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2967337e3fcb228dded64ab0c41a17e0.png)
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解题方法
【推荐1】长方体
中,
,
是对角线
上一动点(不含端点),
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/11/85f6414a-a443-4403-98b3-59fef327f012.png?resizew=171)
(1)若
,求三棱锥
体积;
(2)平面
与平面
所成角的余弦值
,求
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cda540a0258f49af1773ca6c25645067.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/11/85f6414a-a443-4403-98b3-59fef327f012.png?resizew=171)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a741efbdfcd25f34ce2f99a37be9484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec150229429412308f1155f8b098d3ee.png)
(2)平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212a67f115d1cbe69f100b489babe5f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfb3f0b5d8bf98eeff66f43b7dcbb4be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212a67f115d1cbe69f100b489babe5f8.png)
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解题方法
【推荐2】如图,在三棱锥D—ABC中,G是△ABC的重心,E,F分别在BC,CD上,且
,
.
![](https://img.xkw.com/dksih/QBM/2022/3/16/2937568463167488/2938680845516800/STEM/a9bb2de0d4534065ba668f42fc8fe81c.png?resizew=181)
(1)证明:平面
平面ABD;
(2)若
平面ABC,
,
,
,P是线段EF上一点,当线段GP长度取最小值时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91928fb7fc49b70ffd1f3a7dbeb566f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47ad6b6519a55c2a502b9a94d3b514b4.png)
![](https://img.xkw.com/dksih/QBM/2022/3/16/2937568463167488/2938680845516800/STEM/a9bb2de0d4534065ba668f42fc8fe81c.png?resizew=181)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51daddc16eddbdf70ab3c15a28f6286b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d2873cc55831ef240c0e172cf89ae29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d399d731913a563e291b817831a0c678.png)
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解题方法
【推荐1】如图,在三棱柱
中,
平面
,
,
分别是
的中点
![](https://img.xkw.com/dksih/QBM/2020/7/25/2513352610791424/2513778649808897/STEM/20fcdbb9dafd42528395f020b002972d.png?resizew=227)
(1)求证:
平面
;
(2)求直线
与平面
所成角的正弦值;
(3)在棱
上是否存在一点
,使得平面
与平面
所成锐二面角为
?若存在,求出
点的坐标;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcca4982eda404a0cd8193e35a5be6b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ed8f7d3d7043d4b1eb98fc5c4e2fcd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91e1e4115d78e625e9e0f47cdade3286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/450176ba93397527fc3520c55dd1476a.png)
![](https://img.xkw.com/dksih/QBM/2020/7/25/2513352610791424/2513778649808897/STEM/20fcdbb9dafd42528395f020b002972d.png?resizew=227)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92bced6bf70db7229db85f2b10339431.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923189afc198d153c79059a827f63c87.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923189afc198d153c79059a827f63c87.png)
(3)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923189afc198d153c79059a827f63c87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】如图,在直三棱柱
中,
,
,
为棱
上的一点,
分别为
、
的重心.
![](https://img.xkw.com/dksih/QBM/2011/8/28/1570293824184320/1570293829697536/STEM/d6a5d6e29a654ac0bc8df354d69b8e4d.png?resizew=130)
(1)求证:
;
(2)若二面角
的正切值为
,求两个半平面
、
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ed8f7d3d7043d4b1eb98fc5c4e2fcd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/707f1af9b9acd60b98a264a0b767ffbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db5e1441a49e782ff0ef46e776cde06a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efed5a71731fece198572ae508b4ed17.png)
![](https://img.xkw.com/dksih/QBM/2011/8/28/1570293824184320/1570293829697536/STEM/d6a5d6e29a654ac0bc8df354d69b8e4d.png?resizew=130)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f479d987bc7abd828c64f9dc745836ab.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/442af36f0d841dc892f0750462b8a6d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14b8f65872fbe939603c6e2acee74baa.png)
您最近一年使用:0次