在底面是菱形的四棱锥S-ABCD中,已知
,BS=4,过D作侧面SAB的垂线,垂足O恰为棱BS的中点.
![](https://img.xkw.com/dksih/QBM/2021/4/9/2695932021612544/2809220658454528/STEM/d91a1156-f65a-4102-8aa7-3a482c097645.png?resizew=194)
(1)在棱AD上是否存在一点E,使得OE⊥侧面SBC,若存在求DE的长;若不存在,说明理由.
(2)求二面角B-SC-D的平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da05478ac906a1be15a60f629bf08a7.png)
![](https://img.xkw.com/dksih/QBM/2021/4/9/2695932021612544/2809220658454528/STEM/d91a1156-f65a-4102-8aa7-3a482c097645.png?resizew=194)
(1)在棱AD上是否存在一点E,使得OE⊥侧面SBC,若存在求DE的长;若不存在,说明理由.
(2)求二面角B-SC-D的平面角的余弦值.
更新时间:2021-09-16 09:56:58
|
相似题推荐
解答题-问答题
|
较难
(0.4)
名校
解题方法
【推荐1】在三棱柱
中,已知
,点
在底面
的射影是线段
的中点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/8b5bb68b-018d-42cd-bbbf-84c30c711c98.png?resizew=182)
(1)证明:在侧棱
上存在一点
,使得
平面
,并求出
的长;
(2)求二面角
的平面角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54db4980611d321429658d6ed5b1af53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/8b5bb68b-018d-42cd-bbbf-84c30c711c98.png?resizew=182)
(1)证明:在侧棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9de7ea432599108b34a0ccaa0f2c75e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7d9489e5f82b60248c1adfcf299032b.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
名校
【推荐2】如图,在四棱锥
中,底面
是矩形,
,
,
底面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/4543f909-17d5-427c-ba92-0b1894219849.png?resizew=151)
(1)当
为何值时,
平面
?证明你的结论;
(2)若在
边上至少存在一点
,使
,求
的取值范围.
![](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/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e781a2489271bfd1597cba1bb6f5887.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/4543f909-17d5-427c-ba92-0b1894219849.png?resizew=151)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)若在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83abffb64a927cf133022dd88358e7a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
名校
【推荐1】如图,直四棱柱
的底面
是菱形,
是
的中点,
为线段
上一点,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/fe857464-e59e-40b7-97e8-308f734aae33.png?resizew=180)
(1)证明:当
时,
平面
;
(2)是否存在点
,使二面角
的余弦值为
?若存在,请指出点
的位置;若不存在,请说明理由.
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad1a56baf43ffdf67bc8460856e31fec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/fe857464-e59e-40b7-97e8-308f734aae33.png?resizew=180)
(1)证明:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c114237f609956017bc72f4971d5b375.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)是否存在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d31d79927f9b7d0e911af5571e660575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3ffd5c35bba71ea54c28622b6cf505d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】在四棱锥
中,底面
是边长为
的正方形,
是
的中点,点
在棱
上,且
,
,
.
(1)若平面
平面
,证明:
平面
;
(2)求平面
与平面
的夹角的余弦值的最大值.
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.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/db27b7f29d7d01b2692f217bc3079fc4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c31312a64851f9a4d63e34bb73052c77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3ad66112b09c909cab417085702ec00.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/3/6633f89b-4ec6-4678-bc49-2f9394d0e52f.png?resizew=165)
(1)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1084a42a7b7600ac9651a023de6d3401.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebae74545340ce6971f437d129e9c659.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93a4afe69e9ee3c701f1f109c3a0a7d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d246f9eceab371ebf47a47c2f11a4ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
您最近一年使用:0次