如图,在四棱锥
中,
底面
,底面
是直角梯形,
,
,
,点
在
上,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/76d04870-cf92-495e-9973-f89f95d144a7.png?resizew=160)
(1)点
在
上,
,求证:
平面
;
(2)若直线
与平面
所成的角为
,求二面角
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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e57af480a5e2c688723d762b822fa51e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e486a1aad96167ff62f6fb5136e0bb.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/45ab1959f7fa560977ffb9fb0e11bb2c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/76d04870-cf92-495e-9973-f89f95d144a7.png?resizew=160)
(1)点
![](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/8f0ce7aaca2b6725dac7ed5d2a437aa1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a5f445af1ae136773cb338920552ff2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce81faef7c631553e02d7468973a74cd.png)
更新时间:2020-05-08 11:53:28
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】如图,在四棱锥
中,底面
是平行四边形,
平面
,
,
,
是棱
上的一点.
(1)证明:
平面
;
(2)若
平面
,求
的值;
(3)在(2)的条件下,三棱锥
的体积是18,求
点到平面
的距离.
![](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/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/251048aaeb0a16b152152a64d966b4f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c406e7d1e7977dd5b30ef81cfdc8e8d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373f735f0f04d11f1951eaef1bb78b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/add47889f6b4911133999a898d3666d3.png)
(3)在(2)的条件下,三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1112ffa328ed486ffc5e4a605eb510e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/4b5f932f-6c32-4507-8f16-a1d7d9da0252.png?resizew=175)
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2】如图,在四棱锥
中,底面BCDE是平行四边形,
,
,
,点F为棱BE的中点,
.
![](https://img.xkw.com/dksih/QBM/2022/9/2/3057941099962368/3064392448598016/STEM/67b4270a4b7c4be5a4e308bd5ecd7739.png?resizew=254)
(1)证明:
平面ABF;
(2)若
,求直线DF与平面ADE所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5164a3cc47e266446d49127e2ef10c37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b0382c28547d3834ca71f3f0677695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713d4e968d4852e0258aa1307f5d47f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48a277db452e76240ec83ec6a2864bdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/876bb8ce0ca53475fa091ffd18bdc94a.png)
![](https://img.xkw.com/dksih/QBM/2022/9/2/3057941099962368/3064392448598016/STEM/67b4270a4b7c4be5a4e308bd5ecd7739.png?resizew=254)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b190c8d3d7d7d0e6e959e8a52eae90.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
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名校
【推荐3】如图所示,在梯形ABCD中,
,
,四边形ACFE为矩形,且
平面ABCD,
.
![](https://img.xkw.com/dksih/QBM/2022/5/5/2973016492834816/2974529330372608/STEM/837b4fcbfecb4ae888b10f9d10c213b5.png?resizew=191)
(1)求证:
平面BCF;
(2)点M在线段EF上运动,当点M在什么位置时,平面MAB与平面FCB所成的锐二面角为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b0382c28547d3834ca71f3f0677695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac0b72906641ed13716cfbce50923282.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b72f9d26318f501db675074e0dd9356.png)
![](https://img.xkw.com/dksih/QBM/2022/5/5/2973016492834816/2974529330372608/STEM/837b4fcbfecb4ae888b10f9d10c213b5.png?resizew=191)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a5f445af1ae136773cb338920552ff2.png)
(2)点M在线段EF上运动,当点M在什么位置时,平面MAB与平面FCB所成的锐二面角为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d88591679796c52024d11c4de641bdb.png)
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名校
【推荐1】如图,在四棱柱
中,侧棱
底面
,
,
,
,
,且点
和
分别为
和
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/3cfb8594-f881-461d-bbc3-ac7cce38e215.png?resizew=210)
(1)求证:
平面
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c9d5815dc775d5a5810fff0b016a8d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70c2888dad200ebe6cbc60b7a680ad6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e3334853138fb74687d66b1e45f2fd9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/3cfb8594-f881-461d-bbc3-ac7cce38e215.png?resizew=210)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88595db9e3a4bf66275eae21fe0238e7.png)
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【推荐2】如图,在四棱锥
中,平面
平面
,点E在以
为直径的半圆O上运动(不包括端点),底面
为矩形,
.
平面
;
(2)当四棱锥
体积最大时,求平面
与平面
所成夹角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fceb227a6d222aa08c39f2e405aa119.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/662698361c6b3ddaf0c28a3c87be53e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(2)当四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
您最近一年使用:0次