如图,正四棱锥
中.
(1)求证:平面
平面
;
(2)若
,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/5/07e72209-880c-4c06-8e15-ddd3432de5f6.png?resizew=157)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f5019d74a9497f861a0f755ea31d010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
更新时间:2023-09-03 22:44:55
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,圆柱的轴截面
是边长为2的正方形,点
是圆弧
上的一动点(不与
重合),点
是圆弧
的中点,且点
在平面
的两侧.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/23/5d513bf9-f7f1-43b4-a372-7adae49cca2e.png?resizew=188)
(1)证明:平面
平面
;
(2)设点
在平面
上的射影为点
,点
分别是
和
的重心,当三棱锥
体积最大时,回答下列问题.
(ⅰ)证明:
平面
;
(ⅱ)求平面
与平面
所成二面角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39acab3cfb59bfc9591371721ab01d93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6bce3d91ca23b86d8c6625f2632e437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/23/5d513bf9-f7f1-43b4-a372-7adae49cca2e.png?resizew=188)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)设点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64484f96568410926e0c50898eba6e32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7a551505ae42b49904bab59b17012d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e534b545e86c02abd2a0dc75d32b407.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
(ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f947fd286e0c37fdcc8d1b6ce4295c7a.png)
(ⅱ)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.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2】如图,几何体由四棱锥
和三棱台
组合而成,四边形
为梯形,
且
,
,
,
平面
,
,平面
与平面
的夹角为45°.
(1)求证:平面
平面
;
(2)求三棱台
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01441e64b535e914f1c874dfa6aef5f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4c6e25e808b0bb0bcbaefbda0986c25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef699f5dc072b853cfe700c6f1abbbae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e839ac941e8bf536ff35a12e56c7a400.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/755d575f0a87f3345e232b66d5956070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cf187bc2ede965870b90757b495f53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18265a5b0d8251b6fab29e40f46e4c00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8257b6bd25104e07b9ad935c0a3aac4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/8/006c7ac4-b9b2-485a-a133-6df8920d2bcc.png?resizew=133)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39282bdf319f30d7bc261e2e3ab3b1e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce463fb3ce4b3d49d470f66471fe4c15.png)
(2)求三棱台
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4c6e25e808b0bb0bcbaefbda0986c25.png)
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1】如图,在长方体
中,
为线段
的中点,
为棱
的中点,且
.
![](https://img.xkw.com/dksih/QBM/2020/12/24/2621142535888896/2624821634498560/STEM/66b8be49-0da2-4b2b-aa45-6a8c8026287c.png?resizew=389)
(1)证明:
.
(2)若
,
,求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b4afa61e0bcb124aec52ad0cc84fd94.png)
![](https://img.xkw.com/dksih/QBM/2020/12/24/2621142535888896/2624821634498560/STEM/66b8be49-0da2-4b2b-aa45-6a8c8026287c.png?resizew=389)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f88e1c3e5bb643bafcda8f20d6a9a7.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb22fad23b87c643745959334290f5aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5e884ca9429486026caa5e2310b0e4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaacef9fef191e506177936117123cc6.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】如图:斜三棱柱
,底面
为等边三角形,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/2568ca18-ac8c-4edb-acc5-848a7728c8d4.png?resizew=190)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
面
;
(2)若
在底面的投影为
,且二面角
的正切值为2,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42da07fe3eb407f22393fb36723dadd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2d6ceed6e5a36193bcb5a557853dbee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f2678c36c2bbd23adfd65f218e68a69.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/2568ca18-ac8c-4edb-acc5-848a7728c8d4.png?resizew=190)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f77f400a3cf0acb19d4e4c7da2b80a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
您最近一年使用:0次