如图,圆锥
的高为3,
是底面圆
的直径,PC,PD为圆锥的母线,四边形
是底面圆
的内接等腰梯形,且
,点
在母线
上,且
.
(1)证明:平面
平面
;
(2)求平面
与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef49a3ca580a144cc65a609c167facc1.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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6045266f6db39e41b7abde762d9e9a57.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/b5861b1a4a94ec85258132679fb28050.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/4/15e62cfd-ddb8-46c2-9f89-f450bc2c2344.png?resizew=141)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4a46fbde58e12b1edc038ae9e921722.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c15b63176f43bc7a0654d0f6f45e7429.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62871bb0dff211fc3bd80f9066c25b29.png)
更新时间:2023-06-27 22:21:00
|
相似题推荐
解答题-证明题
|
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解题方法
【推荐1】如图,在棱长为a的正方体
中,
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/15/ca149d7a-f4d0-4e33-be9a-5e898c934860.png?resizew=181)
(1)求证:
;
(2)求证:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/15/ca149d7a-f4d0-4e33-be9a-5e898c934860.png?resizew=181)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9136071c4b1bb2c7c09a49aed7338a09.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/565133e91e3ace2b2187cfc6f1db5be6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7977ab975efa6411cc17de39be70d9.png)
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【推荐2】如图,四棱锥
的底面是边长为
的菱形,
,
平面
,
,
为
的中点,
为底面对角线的交点;
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/14/950aedce-02f0-4b7b-a8e5-063dd298f9a5.png?resizew=229)
(1)求证:
平面
;
(2)求二面角
的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b0382c28547d3834ca71f3f0677695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89a2827eae3985793ef13b451fe538ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/14/950aedce-02f0-4b7b-a8e5-063dd298f9a5.png?resizew=229)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/466fabcaac59132fea648ff35342ec9d.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47d294d69caac577339f11f477b2047e.png)
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解题方法
【推荐1】如图,在正方体
中,判断平面
与平面
是否垂直,并说明你的理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e2f7554a52815bfa0f4d75221ba7397.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b4cd2b33bd983a9ed6575b9de04a46a.png)
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【推荐2】如图甲所示,在平面四边形
中,
,现将
沿
折起,如图乙所示,使得
.
![](https://img.xkw.com/dksih/QBM/2022/2/17/2918488845156352/2921042734931968/STEM/a71304a1-e1e0-472a-995c-9119153516ed.png?resizew=315)
(1)求证:平面
平面
;
(2)取
的中点E,
的中点F,
与
交于点G,求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2aecb2b1bd08eacc163f76e3b29006af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e1f4f255d191786f7d330d278868c2d.png)
![](https://img.xkw.com/dksih/QBM/2022/2/17/2918488845156352/2921042734931968/STEM/a71304a1-e1e0-472a-995c-9119153516ed.png?resizew=315)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4739afd7311501e948aa4e1e5c1cb17.png)
(2)取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a7e4a6765ce78b05ee97764771e01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
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【推荐1】如图,在三棱锥
中,平面
平面
,
,O为
的中点,
.
![](https://img.xkw.com/dksih/QBM/2022/5/23/2985417545842688/2985845650292736/STEM/a91b0ac5-fc09-4c84-adfe-4da1010f3b57.png?resizew=177)
(1)证明:
平面
;
(2)点E在棱
上,若
,二面角
的大小为
,求实数
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfffdd6a8ba5a9ba5c99ae87e26db2a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2acc4c5faee54dd596b2458d25341400.png)
![](https://img.xkw.com/dksih/QBM/2022/5/23/2985417545842688/2985845650292736/STEM/a91b0ac5-fc09-4c84-adfe-4da1010f3b57.png?resizew=177)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4317430d5a2b61d9a2a88b73e7d7ad39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)点E在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7a4f6524c94bf8b91a91d9e90f015bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324d453870b345da0c41977290192f94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15615de1a6df206dbd081251f676578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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【推荐2】在平面五边形ABCDE中(如图1),ABCD是梯形,
,
,
,
,
是等边三角形.现将
沿AD折起,连接EB,EC得四棱锥
(如图2)且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/51013e15-55e5-4776-a1c4-84de57308658.png?resizew=317)
(1)求证:平面
平面ABCD;
(2)在棱EB上有点F,满足
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5827a006e69fc21a86abe63f86b7e2c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38c5c9cc1ed4bce98b7fae77e70b227f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/51013e15-55e5-4776-a1c4-84de57308658.png?resizew=317)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3abb27f8d654064a92f9d7a11e586ab5.png)
(2)在棱EB上有点F,满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4f85a3984ff5650e5845789b3b23f99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0730e73ddbbf9184df15d3b1467e55e7.png)
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【推荐3】四棱锥S﹣ABCD如图所示,其中四边形ABCD是直角梯形,AB⊥AD,AD⊥DC,SA⊥平面ABCD,DA=DC
AB=1,AC与BD交于点G,直线SC与平面ABCD所成角的余弦值为
,点M在线段SA上.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/12/c8bf860c-0803-45e7-92ed-38e268e15bd5.jpg?resizew=237)
(1)若直线SC
平面MBD,求
的值;
(2)求平面SBC与平面BCD所成二面角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a50a39604477d1d9326eb455cda2e838.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1174142f3bba761585b6bc2653009b36.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/12/c8bf860c-0803-45e7-92ed-38e268e15bd5.jpg?resizew=237)
(1)若直线SC
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895d6f710d5f67e1d4c7408d50d77281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80b98851cd97e52ae204272ab60a0a4c.png)
(2)求平面SBC与平面BCD所成二面角的正切值.
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