如图所示,三棱柱
中,侧面
是边长为
的正方形,
是菱形,
,且平面
垂直平面
,
为
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/a424b526-09e4-4391-b87d-8065db738581.png?resizew=199)
(1)求证:平面
平面
;
(2)求二面角
平面角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe5f0597fe825e210ff7e075cfa2cd91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/a424b526-09e4-4391-b87d-8065db738581.png?resizew=199)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/819d4f24c9e0f0dd1718912732cfe7ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1654dfe63f11563eadbaee32dae7b1e.png)
更新时间:2020-12-26 20:32:15
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】 如图,已知
平面
是正三角
形,
.
(Ⅰ)在线段
上是否存在一点
,使
平面
?
(Ⅱ)求证:平面
平面
;
(Ⅲ)求二面角
的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbe3ec31a79a171dcf274ff99e50762.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c773f72c053e7287702e3f7e8c236593.png)
形,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f779e7f5f53e4377b9a0a8e945d562.png)
(Ⅰ)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8f70cf3f6c7acbf60d4a4ca0ce89619.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(Ⅱ)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84181cfc406696b59161b8d4c417099c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(Ⅲ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b5a82f851479ec3ae9dc7aca67a97ab.png)
![](https://img.xkw.com/dksih/QBM/2010/4/2/1569689467109376/1569689574719488/STEM/eba6fd8855f449109b673e53ece64459.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,在三棱锥
中,
,
底面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/94726b8b-e1fb-4460-90a3-122a8fae6b8b.png?resizew=172)
(1)求证:平面
平面
;
(2)若
,
是
的中点,记
与底面
所成角为
,
与平面
所成角为
,试研究
与
的等量关系.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ed8f7d3d7043d4b1eb98fc5c4e2fcd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/94726b8b-e1fb-4460-90a3-122a8fae6b8b.png?resizew=172)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc0da97a7aede49990189a2f3293b382.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/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
真题
解题方法
【推荐1】如图,在三棱锥
中,
底面ABC,
.DE垂直平分SC,且分别交AC、SC于D、E.又
.求以BD为棱,以BDE与BDC为面的二面角的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41e5db1d2fd912f77923e4c120a7dc19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10c83f8945042b9c8fb2fbdac9308d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69948bac75c4d742872c326bf1e731d2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/11/037d5a5f-ceed-458f-a3a6-df0188f365eb.png?resizew=160)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,在多面体
中,
平面
,且
是边长为2的等边三角形,
.
是线段
的中点,证明:直线
面
;
(2)求二面角
的平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4c5ae16a7145a28a91d45ef950a07c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0968b39e8d3a5146759340413571d0d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69dc003d123423886dba10b28b10b3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a5f445af1ae136773cb338920552ff2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/780d3f5f4c4419913c1232b7aae03ade.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3db1d8f228c87b65a3609f825fc441d5.png)
您最近一年使用:0次