如图,三棱柱
的侧面
是边长为
的菱形,
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/3/7b61e34e-daed-458b-a568-59fc9a57ab8c.png?resizew=205)
(1)求证:
;
(2)若
,当二面角
为直二面角时,求三棱锥
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/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/900e00a3609e6043af1034761d4d65f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7870cee007535b979d35bc7feab75616.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/3/7b61e34e-daed-458b-a568-59fc9a57ab8c.png?resizew=205)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07e8af8caf4f395dc9a59903a7dba85a.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6997af36a239195f7b55557242cb03c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aab8cba157598642cb6b42734861a184.png)
更新时间:2019-01-26 17:47:03
|
相似题推荐
解答题-问答题
|
较难
(0.4)
解题方法
【推荐1】无数次借着你的光,看到未曾见过的世界:国庆七十周年、建党百年天安门广场三千人合唱的磅礴震撼,“930烈士纪念日”向人民英雄敬献花篮仪式的凝重庄严
金帆合唱团,这绝不是一个抽象的名字,而是艰辛与光耀的延展,当你想起他,应是四季人间,应是繁星璀璨!这是开学典礼中,我校金帆合唱团的颁奖词,听后让人热血沸腾,让人心向往之.图1就是金帆排练厅,大家都亲切的称之为“六角楼”,其造型别致,可以理解为一个正六棱柱(图2)由上底面各棱向内切割为正六棱台(图3),正六棱柱的侧棱
交
的延长线于点
,经测量
,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9edf5b5d5de0dc8433f8e49b93d79e7.png)
![](https://img.xkw.com/dksih/QBM/2023/12/17/3391057551040512/3392644660494336/STEM/739efe31d1324ffd9d0d8369427dc118.png?resizew=150)
![](https://img.xkw.com/dksih/QBM/2023/12/17/3391057551040512/3392644660494336/STEM/5c2e398c19f147dd862e11b4f0819cba.png?resizew=163)
![](https://img.xkw.com/dksih/QBM/2023/12/17/3391057551040512/3392644660494336/STEM/7b665bafb0b246b2953db68d9fcc512c.png?resizew=191)
(1)写出三条正六棱台的结构特征.
(2)“六角楼”一楼为办公区域,二楼为金帆排练厅,假设排练厅地板恰好为六棱柱中截面,忽略墙壁厚度,估算金帆排练厅对应几何体体积.(棱台体积公式:
)
(3)“小迷糊”站在“六角楼”下,陶醉在歌声里.“大聪明”走过来说:“数学是理性的音乐,音乐是感性的数学.学好数学方能更好的欣赏音乐,比如咱们刚刚听到的一个复合音就可以表示为函数
,你看这多美妙!”
“小迷糊”:“.....”
亲爱的同学们,快来帮“小迷糊”求一下
的最大值吧.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eece548f90ab9654e1dd55340431f4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7e4fa04825ac7d071968056322d88be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f92a8ba0b29a1e1eca637c01b7f39b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9edf5b5d5de0dc8433f8e49b93d79e7.png)
![](https://img.xkw.com/dksih/QBM/2023/12/17/3391057551040512/3392644660494336/STEM/739efe31d1324ffd9d0d8369427dc118.png?resizew=150)
![](https://img.xkw.com/dksih/QBM/2023/12/17/3391057551040512/3392644660494336/STEM/5c2e398c19f147dd862e11b4f0819cba.png?resizew=163)
![](https://img.xkw.com/dksih/QBM/2023/12/17/3391057551040512/3392644660494336/STEM/7b665bafb0b246b2953db68d9fcc512c.png?resizew=191)
(1)写出三条正六棱台的结构特征.
(2)“六角楼”一楼为办公区域,二楼为金帆排练厅,假设排练厅地板恰好为六棱柱中截面,忽略墙壁厚度,估算金帆排练厅对应几何体体积.(棱台体积公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7850942557a95467b4159b86c1f25678.png)
(3)“小迷糊”站在“六角楼”下,陶醉在歌声里.“大聪明”走过来说:“数学是理性的音乐,音乐是感性的数学.学好数学方能更好的欣赏音乐,比如咱们刚刚听到的一个复合音就可以表示为函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3387b0d9e635720bbbe3fe28b536200.png)
“小迷糊”:“.....”
亲爱的同学们,快来帮“小迷糊”求一下
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3888740fa8b552b55b4a0c8ae4166007.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】多面体
中,
为等边三角形,
为等腰直角三角形,
平面
,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/6be6fa20-d8cf-48bc-9d86-29a68822ad89.png?resizew=137)
(1)求证:
;
(2)若
,
,求多面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/986ba572d8373df48c996f8c8611498c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c372d059202ec388960b125d4a87dc84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61510c34c5795d7261569b4d09098271.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/810ee7bc82b6f452afb3fc18691abc3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a28d6477c85c5a4ac410a884e92fbe53.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/6be6fa20-d8cf-48bc-9d86-29a68822ad89.png?resizew=137)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38b5c1c5518b9332a2fb209c3621c700.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc1a0e79e49e224c198af0c37405a3ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/beba9c5993784964af81ec070b168456.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/986ba572d8373df48c996f8c8611498c.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
名校
解题方法
【推荐1】如图,在四棱锥
中,平面
平面
,
,
,
,
,
.
平面
;
(2)设
.
①若直线
与平面
所成角的正弦值为
,求线段
的长.
②在线段
上是否存在点
,使得点
,
,
在以
为球心的球上?若存在,求线段
的长;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/283042ce7f0c99597044594b98b33ce0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d79e7020414add95907e061df505ef0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/458e0536de1347270b853869399975e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a22b02f6c8636152aeb62d191251e931.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a109c829d652632a88ade6924fcda206.png)
①若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1443002ab7e16b6ba08366a5c6e57616.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
②在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
名校
解题方法
【推荐2】在菱形
中,已知
,
.
是对角线
上一点,沿
把菱形折成二面角
,将折成二面角后的
点记作
,设
,点
在平面
上的射影记为
.
(1)当
是
的中点时,如图1,求证
平面
;
(2)当
落在菱形的边
上时,如图2,求二面角
的取值范围;
(3)设折痕
与菱形的边
交于点
,求四棱锥
体积的最大值(说明:可以用到必修一探究实践活动中得到的不等式![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d936ea1443a8c881633d5e04fdd3434.png)
).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e918b70b02a73685e3c536c7f380e2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8efa92fbb689ce6f9ab3384918f48774.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3160d33de228937b8a691519fced22e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/15/926446e4-566c-43a8-8e7c-da6d5f318095.png?resizew=342)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/662698361c6b3ddaf0c28a3c87be53e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bf12905647aeeded72bbca21a63f319.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8efa92fbb689ce6f9ab3384918f48774.png)
(3)设折痕
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee724bdc07aa2bacb42d4779585a2a12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d936ea1443a8c881633d5e04fdd3434.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d3ac744d01bdb607d6c2ffd7ef64a24.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
解题方法
【推荐1】在四棱雉
中,四边形
为矩形,
,
,点
为线段
的中点.已知点
在平面
上的射影在四边形
外,且直线
与平面
所成的角为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/4/c141d8be-5aea-4ce2-8ec6-203392112efd.png?resizew=182)
(1)设点
为线段
的中点,求证:
;
(2)求平面
与平面
的夹角
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/f8bb7451bce637c6171cf344eb9de43e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9c3ec174b1ce835cc8737ff6ce57e52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.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/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/4/c141d8be-5aea-4ce2-8ec6-203392112efd.png?resizew=182)
(1)设点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa2a33608f10886dc3e90e5ade3a5b90.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
名校
解题方法
【推荐2】如图,在三棱锥
中,
底面
,
,点
分别为棱
的中点,
是线段
的中点,
.
平面
;
(2)求平面
与平面
夹角的余弦值;
(3)已知点
在棱
上,且直线
与直线
所成角的余弦值为
,求线段AH的长.
![](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/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3b9a4cf42189f9ef786b3c549ecd93e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daffd3935e47228b252568a886df769c.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/dc4627df8ec5432214e7e9bda4ef87b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0701f67727b0fc8100cfb5e20ec27d9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6221be113e161825e54d48a2fb16d516.png)
(3)已知点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eef1f7b9adab87736321e30949a4d668.png)
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