如图,四棱锥
中,四边形
为正方形,
,
分别为
,
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/330e3949-6300-4695-9588-6ada2b344daf.png?resizew=125)
(1)证明:
平面
;
(2)已知
,
,
,求三棱锥
的体积.
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/330e3949-6300-4695-9588-6ada2b344daf.png?resizew=125)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94270844f197d524bf1da4f1385befd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/142b5bb5452fa06ab3d0d556ae1b9088.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3af4a22289b4d4575fbb838f09637416.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecbb2dce15f3d0fe839688575d2a8ff8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbb6b4a013c15ce1c166166fc30355af.png)
更新时间:2020-06-19 19:57:11
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,等腰梯形
中,
,
于点
,
,且
.沿
把
折起到
的位置,使
.
(
)求证:
平面
.
(
)求三棱柱
的体积.
(
)线段
上是否存在点
,使得
平面
.若存在,指出点
的位置并证明;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a59a7d30b877db63279f0b44184da40c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd44a2544888b6bef38bb9d51230c9e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a45024b1f1c50249cc194e8689ec01cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/151020b65382d4d26b06453ca77d9442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/829018a6ca0aff95d89e3f7cd943274e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ef328d61bcf3cece520c35a2ce449ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2de47e6e8128d7aeb2f1877920dc9ff.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b4cc38f853822c6949c9b959b01cdac.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efb7eb9cc38b22a3ac9442e84d47b769.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ca15691dfea154b932004966f2fbca3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2061b9ab3862d9c36d32c4ffef91145a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44043884c1c5f80bfb013d9ddb48e277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://img.xkw.com/dksih/QBM/2018/3/29/1912159129468928/1912657314963456/STEM/d254b12ca9ea4ff6961ee20ba7dddeef.png?resizew=534)
您最近一年使用:0次
【推荐2】如图1,在梯形
中,
∥
,
,线段
的垂直平分线与
交于点
,与
交于点
,现将四边形
沿
折起,使
分别到点
的位置,得到几何体
,如图2所示.
(1)判断线段
上是否存在点
,使得平面
∥平面
,若存在,求出点
的位置;若不存在,请说明理由.
(2)若
,求三棱锥
的体积.
![](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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/002f82b05fc164e17d72092d368857c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39acab3cfb59bfc9591371721ab01d93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c0f067a2a348ceb24a408f82992eab8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85227bdb3148e51177d6e26523cbffd6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/29/e20e4e16-9e07-4bac-97af-2724e27f8806.png?resizew=255)
(1)判断线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589786dd7c3a2679c3230b671cd232d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec1dcba40b263c1119ea0a36651c7812.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c262229271a283b8293fe3f4f57f97e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1769cd4d629d8ffb00e8511cfda306b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fffa26c05e91a5bf38c4810ef775e6ec.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在四棱锥
中,底面
是正方形,
与
相交于点O,F点是
的中点,E点在线段
上,且
.求证:直线
∥平面
.
![](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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65277734669566578cbb7d690bb200fb.png)
![](https://img.xkw.com/dksih/QBM/2022/8/19/3048101419761664/3048728540119040/STEM/aa381894be7046d8bc63e227adbaa211.png?resizew=151)
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,正方体
中,
分别为
的中点.
(1)求证:平面
⊥平面
;
(2)当点
在棱
上运动时,是否都有
∥平面
,证明你的结论;
(3)若
是
的中点,求
与
所成的角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e06947327f4c41340b8713e8a6b4c87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b4cd2b33bd983a9ed6575b9de04a46a.png)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e3334853138fb74687d66b1e45f2fd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99f488b85184d4e9d5fc9ccd0cfda8c5.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e3334853138fb74687d66b1e45f2fd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0ff310aabd2282b539537ebed3f788.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd94d3c3765c52e2d6375f1959686430.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/21/fe8fad2d-ba4e-40e3-bf9e-f4ce5a10a31a.png?resizew=189)
您最近一年使用:0次