一块边长为8的正方形纸片,按如图所示将阴影部分剪下,将剩余的四个底边长为2x的全等的等腰三角形作为侧面制作一个正四棱锥S-ABCD (注:底面为正方形,顶点在底面上的射影是底面中心的四棱锥),F为底边CD的中点.
![](https://img.xkw.com/dksih/QBM/2020/9/7/2544627511353344/2544878578524160/STEM/1b0590f5ad864979b5aecf87e0abc139.png?resizew=314)
(1)过棱锥的高及点F作棱锥的截面(如图),设截面三角形面积为y, 求y的最大值及y取最大值时对应的x值;
(2)在(1)中y取最大值时,是否存在动点Q,它在该棱锥的表面(包含底面ABCD)运动,且FQ
SC?若存在,计算其运动轨迹的长度;若不存在,说明理由.
![](https://img.xkw.com/dksih/QBM/2020/9/7/2544627511353344/2544878578524160/STEM/1b0590f5ad864979b5aecf87e0abc139.png?resizew=314)
(1)过棱锥的高及点F作棱锥的截面(如图),设截面三角形面积为y, 求y的最大值及y取最大值时对应的x值;
(2)在(1)中y取最大值时,是否存在动点Q,它在该棱锥的表面(包含底面ABCD)运动,且FQ
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
更新时间:2020-09-07 22:31:38
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,在棱长为2的正方体
中,
为
中点,
为
中点,
为
上一点,
,
为
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/d1cf3353-d686-4a8c-8bf5-c52b19b23170.png?resizew=176)
(1)证明:
平面
;
(2)求四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b29ec91f3667ac4e509a466060a8baf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/d1cf3353-d686-4a8c-8bf5-c52b19b23170.png?resizew=176)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51ca6d6dcda56b12ec23bbff8fbed1f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e06947327f4c41340b8713e8a6b4c87.png)
(2)求四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3db47ff3da4b81248e7c36004874623.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,在三棱锥
中,
,
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/11/1d3f9d77-9566-43f6-addf-1619d3c71a9c.png?resizew=136)
(1)求证:
平面
;
(2)求直线
和平面
所成的角的大小;
(3)求点
到
重心
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3811f83d6fbdfb138ad5887d3fa05a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cbb05b8b630052ff544249ebd72d95d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/822ba132ca9dd0d4a050659aef3c9b26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/11/1d3f9d77-9566-43f6-addf-1619d3c71a9c.png?resizew=136)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a7442b64b37f685bc3ae88ff450c1a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(3)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05e78042a384255038de485fd7bc0839.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
您最近一年使用:0次
解答题-证明题
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名校
【推荐1】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
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/f8a22a08-8dd6-4a3a-954c-7c662204f382.png?resizew=195)
(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/9367449a5847eade07e69f4feddcb027.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20af148464904e21f4374cc8fb886fba.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/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84f78015d1cce755eae8a2db74106902.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d262480ffb55b7617f44b63f130c154a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/f8a22a08-8dd6-4a3a-954c-7c662204f382.png?resizew=195)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b9d0c688e55286443c9974797fc647f.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8768996ca9a0f2c5d9a19abbd54df.png)
(3)线段
![](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/11d27ff0b39832f094ec51e28721d739.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6114761b369162cda06f08e31c23fc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/258ed4f5282317bb067a41104d559222.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,长方体
中,
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/6/f3f12442-e2f3-4e97-b464-c352a121d79e.png?resizew=220)
(1)求证:
;
(2)求证:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d8fe230436ad83b4bf41047d0333071.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/6/f3f12442-e2f3-4e97-b464-c352a121d79e.png?resizew=220)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bc0db58fa5df4b9fa18dde8af446819.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f81fa367ec317fe2a30142e1c30cce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a1c6340bb12cc1bbcda66ac6745fdc3.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
【推荐3】如图,在几何体
中,四边形
为平行四边形,平面
∥平面
,
、
、
都垂直于平面
,E、F分别为
、
的中点.已知
,
.
![](https://img.xkw.com/dksih/QBM/2022/4/14/2957769509937152/2960025272188928/STEM/30dc6599b7724847b0ebfa11d626cc9a.png?resizew=165)
(1)求证:
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67e05241efa370017b863e6e0fe72bbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6d00ebd235b307e18fd45364091ec6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa8b08a5973c5fb5d9084a2f84df49ec.png)
![](https://img.xkw.com/dksih/QBM/2022/4/14/2957769509937152/2960025272188928/STEM/30dc6599b7724847b0ebfa11d626cc9a.png?resizew=165)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/124b94d4c9318df3e765ef2d3f7d1c8b.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69130cf2e4541c2a849cdc5d2d9dfb92.png)
您最近一年使用:0次