刻画空间的弯曲性是几何研究的重要内容,用曲率刻画空间的弯曲性,规定:多面体顶点的曲率等于2π与多面体在该点的面角之和的差,其中多面体的面的内角叫做多面体的面角,角度用弧度制.例如:正四面体每个顶点均有3个面角,每个面角均为
,故其各个顶点的曲率均为
.如图,在直三棱柱
中,点A的曲率为
,N,M分别为AB,
的中点,且
.
平面
.
(2)证明:平面
平面
.
(3)若
,求二面角
的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1a63ab608517bb10aa036783dfb51f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba7b2dd83fcacead6b6c7733503dfcee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8e79fd1a2ba4245c902b45bf9fc5c7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0211da37e92f915e781691296578ba0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00c25c4259d935d6e6fabe5c3fc1f43c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf0b52ab4b32b650e57f9233c1b9bd30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6c5282bc1ea20767a6c092c22c761ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f95c6dbe3dde6e5b84a240b2baf87201.png)
23-24高一下·吉林·期中 查看更多[3]
更新时间:2024-06-15 17:28:34
|
相似题推荐
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
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/2dd409ca-9dca-4e95-886e-a6e036440b17.png?resizew=198)
(1)求证:
平面
;
(2)若
为线段
的中点,且过
,
,
三点的平面与线段
交于点
,确定点
的位置,说明理由;若点
到平面
的距离为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0bc19ac9bfe0a4a0bf0b955bc774af6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68d31600cba2d5256c7e78b6122d6755.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/2dd409ca-9dca-4e95-886e-a6e036440b17.png?resizew=198)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)若
![](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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](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/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70db40c42655327adee01caedfc9d50c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
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【推荐2】已知三棱锥
中,
平面
,
,
,
为
中点,
为
中点,
在
上,
.二面角
的平面角大小为
.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91f3956f008cc29ca4bae44a087d5427.png)
平面
;
(2)求点
到平面
的距离.
![](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/dc63b945d37ff1fc7c4df312c3c23fd4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/491c3a4f72b84ebadd28b90711435adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3b17ba2410af31808093fc780fd2438.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b796bbaeb8450404c2d146283562006e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1a63ab608517bb10aa036783dfb51f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91f3956f008cc29ca4bae44a087d5427.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb31ef428bd9de9bc875b343feded3c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
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解题方法
【推荐1】如图,在四棱锥
中,
底面
,四边形
中,
,
.
平面
;
(2)设
,若直线
与平面
所成角大小为30°,求线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c21929cd5ce9120fe3b7ac99730b617b.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/08a9f566f9ab9c6f9498d5c69e9e98bd.png)
![](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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
您最近一年使用:0次
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【推荐2】如图,在直角梯形
中,
,
,
,
为
的中点,沿
将
折起,使得点
到点
的位置,且
,
为
的中点,
是
上的动点(与点
,
不重合).
![](https://img.xkw.com/dksih/QBM/2022/7/11/3020349800685568/3021590376185856/STEM/15e75024697146088205af682febbfed.png?resizew=421)
(1)证明:平面
平面
;
(2)是否存在点
,使得二面角
的正切值为
?若存在,确定
点位置;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c30f6595dd643813b11ad71df61a10dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21b5ff288b8b59c0494758ae67bbe10d.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/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.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/377240724a516ade73c383c5d13c65ae.png)
![](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/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://img.xkw.com/dksih/QBM/2022/7/11/3020349800685568/3021590376185856/STEM/15e75024697146088205af682febbfed.png?resizew=421)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dec9c5d7af1c18018bce59adcd761e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)是否存在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1bc8a077869e1b8405a4f1b0622ab95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2967337e3fcb228dded64ab0c41a17e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
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解答题-问答题
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名校
【推荐1】如图,在四棱锥
中,
底面ABCD,
,
,
,
,点E为棱PC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/9/cd7d800a-8b82-4bb4-9b3f-00e4593ae822.png?resizew=190)
(1)证明:
平面PAD;
(2)若F为棱PC上一点,满足
,求三棱锥FABD的侧面FBD与底面ABCD所成二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9060f03b9ee41d70d135b1e1a8902ce9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8ef58be8708144272538ee427fb92c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ba814113887c21637c1954f244812f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/9/cd7d800a-8b82-4bb4-9b3f-00e4593ae822.png?resizew=190)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c372d059202ec388960b125d4a87dc84.png)
(2)若F为棱PC上一点,满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f2a245381e615882ee5feb7793a1df6.png)
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【推荐2】如图,已知等腰梯形
的外接圆圆心
在底边
上,
点
是上半圆上的动点(不包含
两点),点
是线段
上的动点,将半圆
所在的平面沿直径
折起,使得平面
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff14a33c2ffdf20e42171df628622d9d.png)
不可能垂直
;
(2)当
平面
时,求
的值;
(3)设
与平面
所成的角为
,二面角
的平面角为
,其中
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05caddba420260693b284ddedce4e761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/745e0525a41fe2e2a7739c75a942290b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff14a33c2ffdf20e42171df628622d9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bb178784aa857d4d4683e650273f054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df7fdfebdbaddc49e8991ec47d2fb076.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8442b116240c39f98ae6990791f5b3d3.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf702adb116c1e46569eb7050d029f49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84ea10539215794cd76e8b211abd503f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/161add50da85f3a4607383f5681230ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/628560d39eeb0339fa00c9c15ab2c095.png)
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【推荐3】如图,在四棱锥
中,
平面
,底面
是直角梯形,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/3/43eeef45-6de1-4cd9-b44a-9a482c42b51c.png?resizew=208)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
平面
.
(2)若二面角
的正切值为
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.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/8fe19db910be27ec24a950337404e2e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/3/43eeef45-6de1-4cd9-b44a-9a482c42b51c.png?resizew=208)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/715cc9ea5e7d80930284ffb117142770.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/306681bd5aaa51e9c63ab3002e23dec5.png)
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解答题-问答题
|
较难
(0.4)
【推荐1】设P为多面体M的一个顶点,定义多面体M在点P处的离散曲率为
,其中Qi(i=1,2,…,k,k≥3)为多面体M的所有与点P相邻的顶点,且平面Q1PQ2,平面Q2PQ3,…,平面Qk﹣1PQk和平面QkPQ1遍历多面体M的所有以P为公共点的面.
![](https://img.xkw.com/dksih/QBM/2021/1/26/2644514256183296/2689274480451584/STEM/77dd3e01df5541b0ae84c2d5ba3159c6.png?resizew=473)
(1)如图1,已知长方体A1B1C1D1﹣ABCD,AB=BC=1,
,点P为底面A1B1C1D1内的一个动点,则求四棱锥P﹣ABCD在点P处的离散曲率的最小值;
(2)图2为对某个女孩面部识别过程中的三角剖分结果,所谓三角剖分,就是先在面部取若干采样点,然后用短小的直线段连接相邻三个采样点形成三角形网格.区域α和区域β中点的离散曲率的平均值更大的是哪个区域?(确定“区域α”还是“区域β”)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c57c421ccb636f7d56e47b8b39feb6c7.png)
![](https://img.xkw.com/dksih/QBM/2021/1/26/2644514256183296/2689274480451584/STEM/77dd3e01df5541b0ae84c2d5ba3159c6.png?resizew=473)
(1)如图1,已知长方体A1B1C1D1﹣ABCD,AB=BC=1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c3a9df7d8e2ad07128d69fb50962a4b.png)
(2)图2为对某个女孩面部识别过程中的三角剖分结果,所谓三角剖分,就是先在面部取若干采样点,然后用短小的直线段连接相邻三个采样点形成三角形网格.区域α和区域β中点的离散曲率的平均值更大的是哪个区域?(确定“区域α”还是“区域β”)
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解答题-问答题
|
较难
(0.4)
【推荐2】蜂房是自然界最神奇的“建筑”之一,如图1所示.蜂房结构是由正六棱柱截去三个相等的三棱锥
,
,
,再分别以
,
,
为轴将
,
,
分别向上翻转
,使
,
,
三点重合为点
所围成的曲顶多面体(下底面开口),如图2所示.蜂房曲顶空间的弯曲度可用曲率来刻画,定义其度量值等于蜂房顶端三个菱形的各个顶点的曲率之和,而每一顶点的曲率规定等于
减去蜂房多面体在该点的各个面角之和(多面体的面角是多面体的面的内角,用弧度制表示).
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/a92b50df-d218-42a5-9a1b-745e46427d6b.png?resizew=452)
(1)求蜂房曲顶空间的弯曲度;
(2)若正六棱柱的侧面积一定,当蜂房表面积最小时,求其顶点
的曲率的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/653c6425ba284719913a5ba89b76d148.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d22678c6aa7bc1b372fa8f46a596be59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db8eccace9994691c9219e098b574c65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1642eec556eb252de9c1ab7bb5ca90b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17eba1a234a34ceeb44bcd15216a2866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d218d925d9bdfbafd000c5cbd7787d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5ec26174ee387a474d3e264ff2e9205.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfe639eab78eafd2d40ea70aa5d3f21d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67716ac738ee2911a69bf4063110a5bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf3834d7ec7531f3c3c0ce9b286f7a49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e9fdc1f8ed0ae44b54a9a2a3aca2db4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/a92b50df-d218-42a5-9a1b-745e46427d6b.png?resizew=452)
(1)求蜂房曲顶空间的弯曲度;
(2)若正六棱柱的侧面积一定,当蜂房表面积最小时,求其顶点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
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【推荐3】人类对地球形状的认识经历了漫长的历程.古人认为宇宙是“天圆地方”的,以后人们又认为地球是个圆球.17世纪,牛顿等人根据力学原理提出地球是扁球的理论,这一理论直到1739年才为南美和北欧的弧度测量所证实.其实,之前中国就曾进行了大规模的弧度测量,发现纬度越高,每度子午线弧长越长的事实,这同地球两极略扁,赤道隆起的理论相符.地球的形状类似于椭球体,椭球体的表面为椭球面,在空间直角坐标系下,椭球面
,这说明椭球完全包含在由平面
所围成的长方体内,其中
按其大小,分别称为椭球的长半轴、中半轴和短半轴.某椭球面与坐标面
的截痕是椭圆
.
(1)已知椭圆
在其上一点
处的切线方程为
.过椭圆
的左焦点
作直线
与椭圆
相交于
两点,过点
分别作椭圆的切线,两切线交于点
,求
面积的最小值.
(2)我国南北朝时期的伟大科学家祖暅于5世纪末提出了祖暅原理:“幂势既同,则积不容异”.祖暅原理用现代语言可描述为:夹在两个平行平面之间的两个几何体,被平行于这两个平面的任意平面所截,如果截得的两个截面的面积总相等,那么这两个几何体的体积相等.当
时,椭球面
围成的椭球是一个旋转体,类比计算球的体积的方法,运用祖暅原理求该椭球的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7539a15ad0db606a6fff7a0b46778a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/028f9f11ca2294b1b530d141c492eac1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/277b835e4ccd3eb574ece09ad834f0de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ff1455a4045eb93f482c0751840aea7.png)
(1)已知椭圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dd54b9df3402ad91e2d34c40efe0c7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2752e086b85f9fbb95010bf771072af9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a46c2737bf9c790cdb4b767217719452.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5076289823db419f94e9c0c8f4aafd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a5e0a51c9e14fb246b0ba0b231c1e3.png)
(2)我国南北朝时期的伟大科学家祖暅于5世纪末提出了祖暅原理:“幂势既同,则积不容异”.祖暅原理用现代语言可描述为:夹在两个平行平面之间的两个几何体,被平行于这两个平面的任意平面所截,如果截得的两个截面的面积总相等,那么这两个几何体的体积相等.当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b05d3b8f5c9df891ef6fbcaf12f43207.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b94469fd19f40116e2dec334919d6586.png)
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