如图,在三棱锥
中,
,其余各棱的长均为2.
(1)证明:
;
(2)若
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/196593a2edd5bbfced2a212cd19b1917.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/2/4e2de542-4b31-4e1a-aa4f-041131d92c27.png?resizew=210)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfc1f76257275ab4b04f9bc913535670.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f5b763032c085a1e60822d8dc1b3605.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
更新时间:2023-08-01 18:01:14
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图所示,点P在圆柱的上底面圆周上,四边形ABCD为圆柱的下底面的内接四边形,且AC为圆柱下底面的直径,PD为圆柱的母线,且
,圆柱的底面半径为1.
![](https://img.xkw.com/dksih/QBM/2022/1/18/2897255238598656/2901521963900928/STEM/6950ed55-9d36-47cf-ad98-f6e8dbb63740.png?resizew=141)
(1)证明:
;
(2)
,B为
的中点,点Q在线段PB上,记
,求多面体PQACD的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e0f73b3c63084d9c032802e01f9a168.png)
![](https://img.xkw.com/dksih/QBM/2022/1/18/2897255238598656/2901521963900928/STEM/6950ed55-9d36-47cf-ad98-f6e8dbb63740.png?resizew=141)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf6c62979a7aa534a191d8387a741e8.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a88c44f558705de3bcefcfc0ece96b8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/667349d99185bb045030b733352ff7fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac42517cf387345689e1457f62a80ec1.png)
您最近一年使用:0次
【推荐2】如图,
为圆锥的顶点,
,
为底面圆两条互相垂直的直径,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/27/c9c3ef34-e876-4900-b6fd-2d5f06a4d927.png?resizew=184)
(1)证明:平面
平面
.
(2)若
,且直线
与平面
所成角的正切值为
,求该圆锥的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/27/c9c3ef34-e876-4900-b6fd-2d5f06a4d927.png?resizew=184)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,在直三棱柱
中,
,
,F为棱
上一点,
,连接AF,
.证明:平面
平面
;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/460ceab4287ab7946cee6fc99b60e0b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac2ae98eb223b4fe33e53e9d3ba4cc40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4280be91682e5d8a0d0704190319bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/456175ea34492f0bc025aaab668fa659.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac7e0a76186e549951b65b9edfa30ea8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/21/4509290a-4cf9-41d0-8f10-ed76db958add.png?resizew=149)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,三棱柱
中,已知四边形
是菱形,
与
交于点
,且
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2018/7/24/1995161909895168/2001079646609408/STEM/4eea60ed794b4427b35359734ae086dd.png?resizew=221)
(1)连接
,证明:直线
平面
.
(2)求平面
和平面
所成的角(锐角)的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a9f99fb3252a4b3b7a62e8a675ddce9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d4d8707d92f4abfcd6065b59542f7b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a909d59728483521a7ad892babd388a6.png)
![](https://img.xkw.com/dksih/QBM/2018/7/24/1995161909895168/2001079646609408/STEM/4eea60ed794b4427b35359734ae086dd.png?resizew=221)
(1)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdc93e193fad261689949a52819753f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eeebdf3d00c146a1b4d220909d7573c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd06851d747f8ccf046bc807b2523e65.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a211ad5a06b505b8365a62c1946f3cb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】如图,在三棱锥
中,
底面
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/2/d4c436cb-369e-4493-8fc7-81559114ba46.png?resizew=118)
(1)求
;
(2)若点
在线段
上,记
的周长为
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bae7599ad243c12d94325ad917f0a44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/853b60fafb31cab8f1bec5510bf1c984.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07abc09e1f0bf5eb87259e3381b3316a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/2/d4c436cb-369e-4493-8fc7-81559114ba46.png?resizew=118)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66989dcdd7cf282905ef78b5d921288a.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dddb32a7a5c157fdf8aa049b2d665b4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9db64408d9857b2a037ead6520d0fa30.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图所示,四棱锥
的底面
是直角梯形,
,
,
,
底面
,过
的平面交
于
,交
于
(
与
不重合).
![](https://img.xkw.com/dksih/QBM/2015/6/4/1572118990372864/1572118996107264/STEM/204d0443060c447fac05a8b29e87d70e.png?resizew=284)
(Ⅰ)求证:
;
(Ⅱ)求证:
;
(Ⅲ)如果
,求此时
的值.
![](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/ae1e04eeb4de72e5750dae77bcb6f88a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d78aafccd397e9c88a567abf4993d40f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/2015/6/4/1572118990372864/1572118996107264/STEM/204d0443060c447fac05a8b29e87d70e.png?resizew=284)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6992555878dbb49a22e02435d3072b74.png)
(Ⅱ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d50a68fed1c23837d1267bdda5c1962.png)
(Ⅲ)如果
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d3f843b83e62bab294988a7ea134a63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47548785e478bc5b9591341a881e3127.png)
您最近一年使用:0次