在《九章算术》中,将底面为长方形且有一条侧棱与底面垂直的四棱锥称为“阳马”.如图,在“阳马”
中,侧棱
底面ABCD,且
.
![](https://img.xkw.com/dksih/QBM/2022/2/10/2913518330667008/2926099554402304/STEM/0c626e5401cb41e8a1f2b729c13bac2d.png?resizew=156)
(1)若
,试计算底面ABCD面积的最大值;
(2)过棱PC的中点E作
,交PB于点F,连DE,DF,BD.若平面DEF与平面ABCD所成锐二面角的大小为
,试求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e2267c84394668eff2e9f5918de4fb.png)
![](https://img.xkw.com/dksih/QBM/2022/2/10/2913518330667008/2926099554402304/STEM/0c626e5401cb41e8a1f2b729c13bac2d.png?resizew=156)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89b336e518ac4ff04c6c26e4b8a15844.png)
(2)过棱PC的中点E作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a4a6a1e70241d600bc6c104313eac61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1a63ab608517bb10aa036783dfb51f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54625f5af5647c5dad88675510c4711b.png)
更新时间:2022-02-28 13:07:41
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】在
中,
分别为角
的对边,且满足
.
(1)求角
的值;
(2)若
,求bc的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/155ecc4a22a0933429ed61e214a7aa27.png)
(1)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8120119749d4bc28067e73fca7d46cd.png)
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解答题-应用题
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适中
(0.65)
【推荐2】喷绘在商业广告、宣传等领域应用广泛,喷绘画面是使用喷绘机打印出来的.喷绘机工作时相当于一条直线(喷嘴)连续扫过一张画布,一家广告公司在一个等腰△AOB的画布上使用喷绘机印刷广告,画布底角
,底边
米,如图所示,记△AOB位于直线
左侧的图形面积为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/17/34e0ef9c-1a60-4bb0-af19-21c3dbc0c888.png?resizew=166)
(1)试求函数
的解析式;
(2)定义
为“平均喷绘率”,求平均喷绘率的峰值(即最大值).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6131160eaee962470abc7771df265c6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6e3dfcd8aff269dd5aba398816490c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6375311b3fcd1df84fa8e4e2bfe17c87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acb17843c51402a1f7cd9b07542597b9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/17/34e0ef9c-1a60-4bb0-af19-21c3dbc0c888.png?resizew=166)
(1)试求函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acb17843c51402a1f7cd9b07542597b9.png)
(2)定义
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69cb8d5a4ddcaf8143b379b86a541861.png)
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解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图①,在正方形
中,E,F分别是边
的中点,将
沿
折起,使得
为正三角形,如图②所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/c7d17a2b-e009-4de3-8bb0-a2763b973037.png?resizew=221)
(1)证明:点A在平面
内的射影G在直线
上;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c4cd264c97c1f261229925cc5a6761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/c7d17a2b-e009-4de3-8bb0-a2763b973037.png?resizew=221)
(1)证明:点A在平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
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】已知三棱台
如图所示,其中
,
.
平面
,且
,求证:直线l⊥平面ABC;
(2)若平面ABC与平面
之间的距离为3,求平面
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31cc997267b98acf44caf43464b30765.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad411eb561f5a503b9c3d5c520200bef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10e0019e49f673a3b11a4259ce3c9a87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5f56d4a08e50b95c1033c1ea3380c64.png)
(2)若平面ABC与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e6a51a168f6a3c308fcfcede6406aa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e2f7554a52815bfa0f4d75221ba7397.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】已知在梯形
中,
,
分别为底
上的点,且
,
,
,沿
将平面
折起至平面
平面
.
![](https://img.xkw.com/dksih/QBM/2018/5/27/1954538529038336/1958145017618432/STEM/8068a5d31bc04c8fabe556d76d5c37c9.png?resizew=326)
(Ⅰ)求证:平面
平面
;
(Ⅱ)若二面角
的余弦值为
,求
的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5408641691fd27f6dd8cf0ab2043ad4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3b96dce1ec94eb90c243b2eddb78476.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da988eac2b646bd694e50e6a58f61c7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e60158453fd24b1af2f4f65a3d2e46d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c2ab52458f2785f307b7742f304ff5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fbdd599f5f5b7dc2f89c616b4361e41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0215e13a9fb5574d5194aeb9507a98aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8057131f4bae6260aaeda1eb3c77fb7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ba3fc3042013acf7dfbd895cb58abc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e64f5fd229218d333adbe9b324e80157.png)
![](https://img.xkw.com/dksih/QBM/2018/5/27/1954538529038336/1958145017618432/STEM/8068a5d31bc04c8fabe556d76d5c37c9.png?resizew=326)
(Ⅰ)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bea9277fccf08e98981c3c8f2944cf1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78d0399ee96906cb1ab244c06ab81362.png)
(Ⅱ)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc8edb91efbc4532ce2f9e3704ccb2a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b20b36dccaf83fc2f486b89330980df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
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,在四棱锥
中,底面
为正方形,
底面
,
,
为线段
的中点,若
为线段
上的动点(不含
).
![](https://img.xkw.com/dksih/QBM/2022/4/16/2959376716955648/2960006621716480/STEM/a23e141c-abf9-4b1e-acd7-750c98d185e8.png?resizew=210)
(1)求证:平面
平面
;
(2)若
,
为何值时,二面角
为
.
![](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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/829f9180ddd9aa1a0ee0dc520f4e0b5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://img.xkw.com/dksih/QBM/2022/4/16/2959376716955648/2960006621716480/STEM/a23e141c-abf9-4b1e-acd7-750c98d185e8.png?resizew=210)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6501f1c913a4ef64957a2f01ab5baa15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/064ba24f1f98e46d5176d1c7d65aff62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e07434597c6894a339e3714fa780f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】如图,四边形
是边长为
的正方形,
将三角形
沿
折起使平面
平面
.
![](https://img.xkw.com/dksih/QBM/2021/3/28/2687780734476288/2688161204936704/STEM/86396b6a-8485-4b21-93f3-bc3824ec48d5.png?resizew=578)
(1)若
为
上一点,且满足
,求证:
;
(2)若二面角
的余弦值为
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba122511a29908f5f3c16a979afc0340.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2021/3/28/2687780734476288/2688161204936704/STEM/86396b6a-8485-4b21-93f3-bc3824ec48d5.png?resizew=578)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d79a2100ec3a85bab03f88f23bd0b20e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10993b2fe5cbc3207e0a12943adfde55.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1069d514c3c32aeabd274475ee209ed6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d77d19204d12a34986025a453e2f3de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
您最近一年使用:0次