名校
1 . 如图,在四棱锥
中,四边形
为正方形
为等边三角形
分别是
和
的中点.
(1)求证:直线
平面
;
(2)若
求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a7e7211d87f8e44dd5d61ce4f6c8ffc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29560ed838ea0c239351c94d23945a2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/6/6/abc4db76-cd11-43ef-9739-9420097d6286.png?resizew=142)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45d7c56ff7012053b6db5073df693800.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/422210c777ac0d625bbd81cc7601bf9b.png)
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名校
解题方法
2 . 在
中,角
的对边分别为
且
若三角形的面积为
且
则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
_________________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7132c2d8b2ff504e6c2ba36c4f6dcfaf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c48d400297f423dafde78aba92a7195.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11a10139dcd7321d24dc9f41606203a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4121fecca5afea0ca688575de00923e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
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3 . 在
中,角
的对边分别是
,已知
,且
.
(1)求角
的大小;
(2)若
,求
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/823a4bcba474434e4d403fc35ee7f19d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff400c098ae6bf6abd24651a5a21114e.png)
(1)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc11331a7b2d2619b40ee6d34c3bd620.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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4 . 在棱长为4的正方体
中,
分别为线段
上的动点,点
为侧面
的中心,则
的周长的最小值为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bb448256c4b8fe2968ee34e19a667ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcc869125145c0139d92490a41bd3918.png)
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5 . 如图,在平面四边形
中,
为钝角三角形,
,则四边形
的面积的最大值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bb7c52a0dbf2cf1ca99cef32c4d22c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be87f288b6a6b95e5ab037f79efbe9be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
A.1 | B.![]() | C.![]() | D.![]() |
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6 . 欧拉线定理指出三角形的外心、垂心、重心都在同一条直线士,且重心与外心之间的距离是重心与垂心之间的距离的一半.设
分别是
的外心、垂心和重心,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/142ed63468aef6c032805e94f17fe33b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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7 . 在正三棱锥
中,
,则下列结论正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
A.若![]() ![]() ![]() |
B.若二面角![]() ![]() ![]() ![]() |
C.荅![]() ![]() ![]() |
D.若![]() ![]() ![]() |
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8 . 若复数
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7fe1ccec018358701090effa2f3a93c.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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9 . 已知复数
在复平面内对应的点分别为
,若
,则实数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
__________ ;若
,则实数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5274f9384f8a7dd28ecf13f9ffbc87b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c82a10b4f0c9323d726804c89dd9548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32458db21db3e131308b31f48353fbb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2945cbc4ff0cb87a163b660d7b8d07fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
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解题方法
10 . 正五角星是一个非常优美的几何图形,且与黄金分割有着密切的联系.在如图所示的正五角星
中,
是该正五角星的中心,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e87f8786b470049e95a8c8a66ad2c00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a425c40b0c3b5c3365a98dbc348b291e.png)
A.![]() | B.![]() | C.12 | D.18 |
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