如图,在四棱锥
中,
平面
,底面
是菱形,
,
.
![](https://img.xkw.com/dksih/QBM/2017/8/12/1750650286333952/1751319789608960/STEM/030cdb189100487fb1c6f3ab5a98645e.png?resizew=192)
(1)若
,求
与
所成角的余弦值;
(2)当平面
与平面
垂直时,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d31b450a8d88e9a289f814d30ea7e2fb.png)
![](https://img.xkw.com/dksih/QBM/2017/8/12/1750650286333952/1751319789608960/STEM/030cdb189100487fb1c6f3ab5a98645e.png?resizew=192)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/829f9180ddd9aa1a0ee0dc520f4e0b5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(2)当平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/218054144a13435580cd132b9459546c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
更新时间:2017-08-13 18:12:08
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,圆柱
内有一个直三棱柱
,三棱柱的底面为圆柱底面的内接三角形,且
是圆
直径,
.
分别为
上的动点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/b80ae0f8-661f-45b3-be86-24e94c2094f0.png?resizew=152)
(Ⅰ)若该圆柱有一个内切球,求圆柱的侧面积和内切球的体积.
(Ⅱ)在(Ⅰ)的条件下,当
时,求异面直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/192f4f9446c954a291f779d963f90257.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/927729940a1598d48e1b6ebc1c2f78ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e675a92cad72c65aa4071b9d9e226090.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/533f1f6ead0d794bb7c70cce9173d4a5.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/b80ae0f8-661f-45b3-be86-24e94c2094f0.png?resizew=152)
(Ⅰ)若该圆柱有一个内切球,求圆柱的侧面积和内切球的体积.
(Ⅱ)在(Ⅰ)的条件下,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/348fb71fbc47fd87e9ce011652ef4186.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f1158eaa2e338f564eb18de5bef1d25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/456175ea34492f0bc025aaab668fa659.png)
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解答题-问答题
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解题方法
【推荐2】如图,在长方体
中,
,
,点
在
上,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/6cda8176-bc08-42b1-98a4-a514f6afb462.png?resizew=188)
(1)求直线
与
所成角的大小;
(2)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/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6155f82a6f64b20085976cea9b64193.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1364213f546b37f8764ddcb59e36ae4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/6cda8176-bc08-42b1-98a4-a514f6afb462.png?resizew=188)
(1)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f233b375753611ffa7a93c2c12ef5e28.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,已知直三棱柱
中,
,
,E,F分别为AC和
的中点,D为棱
上的一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/6bec61c5-ec88-4e16-83d6-b64bfdccf1cd.png?resizew=157)
(1)证明:
;
(2)当平面DEF与平面
所成的锐二面角的余弦值为
时,求点B到平面DFE距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b51da47ab8433342f7a319e412fefae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/6bec61c5-ec88-4e16-83d6-b64bfdccf1cd.png?resizew=157)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a7a3dc3f3a02f4400e22dec2f2fee23.png)
(2)当平面DEF与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1174142f3bba761585b6bc2653009b36.png)
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解答题-证明题
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适中
(0.65)
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解题方法
【推荐2】在如图所示的多面体中,四边形ABEF为正方形,平面ABEF⊥平面CDFE,
,EF=2CD=2,且DF⊥AE.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/25/ae319857-2e09-4f74-88ba-c03fe583f03c.png?resizew=149)
(1)求证:平面ADF⊥平面ABEF;
(2)若二面角C-AE-F的余弦值为
,求该多面体的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c11e72609ba0fbefe03c9f24165cbf11.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/25/ae319857-2e09-4f74-88ba-c03fe583f03c.png?resizew=149)
(1)求证:平面ADF⊥平面ABEF;
(2)若二面角C-AE-F的余弦值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba3dc0a411f385c4df07613b4b54b0c6.png)
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(0.65)
【推荐3】如图,在直三棱柱
中,
,E为
的中点,平面
平面
.
;
(2)若
的面积为
,试判断在线段
上是否存在点D,使得二面角
的大小为
.若存在,求出
的值;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4339a40ae9d1947ec3a4b3e2fa3a16cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21dee56b9f36ba8f76fe67b76383636b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e3f5dc11efe60b4fd9a13b1d6b83842.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e827641feb4179bca7033ed8760bf728.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bacae35b6e16a0a33c2bdc6bc07df7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f1854ba6cc92481d7a616bd2788a47e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0211da37e92f915e781691296578ba0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f633632c5bb6c44a504c1bd5984ff5e2.png)
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