如图,平面
平面
,且四边形
与四边形
是正方形.
![](https://img.xkw.com/dksih/QBM/2021/12/24/2879279450431488/2880138859667456/STEM/9ae3fc0d-0973-4969-9264-f95dda6e81ef.png?resizew=184)
(1)求证:平面
平面
;
(2)若
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa0230288ef43f4dcbfc0a5d030a4afd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa0230288ef43f4dcbfc0a5d030a4afd.png)
![](https://img.xkw.com/dksih/QBM/2021/12/24/2879279450431488/2880138859667456/STEM/9ae3fc0d-0973-4969-9264-f95dda6e81ef.png?resizew=184)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37445be3ae01cb78259c1ee7c0e2e8d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1953be42cd629684fea9a22a423ecb2b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc3032c7935adaaa2d3c17bd7bcb5fbf.png)
更新时间:2021-12-25 14:40:25
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,在四棱锥
中,底面
为平行四边形,
,
,
底面
,
为
上一点,且
.
![](https://img.xkw.com/dksih/QBM/2017/12/20/1842618598187008/1843754966663168/STEM/3081d3d813c944799a6e26e030bd1420.png?resizew=93)
(1)在
上是否存在点
,使得
平面
?若存在,求出点
的位置;若不存在,请说明理由.
(2)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/ea4f5eec0addba78f2e0cdfb7ecc59a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33693cec840a94ab7d4531c160ac8aff.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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b384315ba84cafb978ef3619c8162b5.png)
![](https://img.xkw.com/dksih/QBM/2017/12/20/1842618598187008/1843754966663168/STEM/3081d3d813c944799a6e26e030bd1420.png?resizew=93)
(1)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45fbffb9e2c7fa7c5006cde8da0cabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa3254460ecbacecb3e57c5dce227f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/186ac4570ee586019a8e292ab07d23ab.png)
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适中
(0.65)
【推荐2】如图,在直三棱柱
中,
.
![](https://img.xkw.com/dksih/QBM/2022/9/2/3057656102273024/3058567951220736/STEM/cdbc670346c34504a078ffa413516fa5.png?resizew=176)
(1)证明:
;
(2)若三棱锥
的体积为
,求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8b183b8391f5d9b2b7c4c6e7a7e6f35.png)
![](https://img.xkw.com/dksih/QBM/2022/9/2/3057656102273024/3058567951220736/STEM/cdbc670346c34504a078ffa413516fa5.png?resizew=176)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47af45fbf1714055d9b414a44a8613fa.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/095cc9746488584e6b878e5a6dfe9f35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24c14ff9b66f21c05e52dc3c8908c2df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a90bf62a5229257b6ed65f3a47873dd3.png)
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解题方法
【推荐1】如图,四棱锥
中,底面
是边长为2的菱形,
,
,
.
平面
;
(2)若
,求二面角
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/05740f0c6071846227dc0ec177ad15e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83640592853a53872d7af69c0cffc1bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2899e607479d8d1c47d954ae9ebb7144.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63e4d19bf237a6fca67e0d01a9ddb726.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a65bf87f74420270138ed73a2d38ca48.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
解题方法
【推荐2】四棱锥
中,
交于点
,且
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/30/e3d51a86-7bf4-44c9-8cf9-3571460767de.png?resizew=226)
(1)若
为
中点,求证:
平面
.
(2)当三棱锥
的体积最大时,求三棱锥
的体积,并证明:平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3c032441543354c154ee67d744abb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b39321a5d88a96b638bf95bc1c6ca41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b67f57cbb3e05dd845bd4f31493d2ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/30/e3d51a86-7bf4-44c9-8cf9-3571460767de.png?resizew=226)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)当三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08a9ec3b527947cad9caa4537e0cb7e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f11bfca0b64b54b4b804e460162dc81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65277734669566578cbb7d690bb200fb.png)
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【推荐1】在三棱锥
中,平面
平面
,
,
,
分别是棱
,
上的点
![](https://img.xkw.com/dksih/QBM/2020/1/2/2368530279997440/2369360141017088/STEM/a721d1c04dd34b11a4f2c29802780e49.png?resizew=152)
(1)
为
的中点,求证:平面
平面
.
(2)若
,
平面
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6a94d59dee2d5a8f0425b64b2083825.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8704811c9c5dba854310ae0de2ba6b05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d89ba4036a5d18ec4abed44d7fd8e89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c14427faad52b64c142facdaccb3b7a.png)
![](https://img.xkw.com/dksih/QBM/2020/1/2/2368530279997440/2369360141017088/STEM/a721d1c04dd34b11a4f2c29802780e49.png?resizew=152)
(1)
![](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/90cacdef2c5f2a4b00a1f4f3fe77bd9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f526e2fe627bb4ddebe708c07d0a22fc.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68fb8a3d21d1379330661ee0b91ee0a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d319b19eb495979429603fe057375f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08452588675f76da2f8d31387b3a8224.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84476b47460d0222eb7f7374db64113f.png)
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解答题-证明题
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适中
(0.65)
【推荐2】如图,SD垂直于正方形ABCD所在的平面,AB=1,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4d51be6693288c423b4bdd106e3ef5d.png)
![](https://img.xkw.com/dksih/QBM/2011/5/12/1570192810598400/1570192815865856/STEM/8a08481478814f158bd936a7cfc32c21.png?resizew=135)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1197dd6b99f28faac2cade24b7d52229.png)
(2)设棱SA的中点为M,求异面直线DM与SC所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4d51be6693288c423b4bdd106e3ef5d.png)
![](https://img.xkw.com/dksih/QBM/2011/5/12/1570192810598400/1570192815865856/STEM/8a08481478814f158bd936a7cfc32c21.png?resizew=135)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1197dd6b99f28faac2cade24b7d52229.png)
(2)设棱SA的中点为M,求异面直线DM与SC所成角的大小.
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