解题方法
1 . 如果
,
是两个单位向量,那么下列四个结论中错误的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c5562bd4d1b54424330cb6329cd79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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解题方法
2 . 在
中,角
,
,
的对边分别为
,
,
.若
,
.
(1)若
为锐角三角形时,求边
的取值范围;
(2)求
面积的最大值;
(3)在(1)的条件下,若
,
分别为
,
的中点,连接
,
交于点
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03837b3769eda7f0d3804cc5ad4a6d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05fccb8041c4caf53dc199b1cba2e062.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(3)在(1)的条件下,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.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/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9d529116469135597c7bf6455625d39.png)
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3 . 如图,在平行四边形
中,
为
的中点,
为
上一点且满足
,
,
.
,
表示
,
;
(2)若
,
,求向量
,
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64f978a9608d6e9d5c0c67fceb5e57c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f3adc4ed291596abf3bb93ae7a075d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/184359fe3cadc363cf4ebe586c2b3db4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c5562bd4d1b54424330cb6329cd79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c94075193c11fe43f2396cff5a485054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba7d3a0680780aaf4549c447fe8dfe9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b95278c67ae9f17b640caab6c8ec418c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa1466856bf2570685d3629c1f813748.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de745f4a313e835454881b20c7fabeb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba7d3a0680780aaf4549c447fe8dfe9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b95278c67ae9f17b640caab6c8ec418c.png)
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4 . 如图,2024年元宵节在浙江桐乡凤凰湖举行“放孔明灯”活动.为了测量孔明灯的高度,在地上测量了一根长为200米的基线
,在点
处测量这个孔明灯的仰角为
,在
处测量这个孔明灯的仰角为
,在基线
上靠近
的四等分点处有一点
,在
处测量这个孔明灯的仰角为
,则这个孔明灯的高度![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6a548e8a2e2205f2faa87e25180a083.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6ec007c9c7ce7e13af3ca8b84c64ef6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcc0c3626d9b2c9cc92403e99e727912.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32c0b52fdca650c96f803556a514b08f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6a548e8a2e2205f2faa87e25180a083.png)
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解题方法
5 . 已知圆台的上、下半径分别为
,
,
.若一个球与圆台上、下底面及侧面均相切,则该球的表面积为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3e95410f3b4fcb0cba425b521d1f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8274868fe4b385843e0fe3c64322a55.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
6 . 在平行四边形
中,
,
,则用
,
表示向量
和
分别是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e55362a3a1f592e6551851c42d3078.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8682ba80b5d1e124e98c8661c753a19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c5562bd4d1b54424330cb6329cd79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/304a7f07db2ec637baadf8f0ab91c85c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abcb5d89b04570ceda2c29e11cb27a57.png)
A.![]() ![]() | B.![]() ![]() |
C.![]() ![]() | D.![]() ![]() |
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7 . 在△ABC中,角A,B,C的对边分别为a,b,c,若
,则△ABC一定是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/185b302f52b77a3e3d0364f73f5b3d92.png)
A.等腰三角形 | B.直角三角形 |
C.等腰或直角三角形 | D.等边三角形 |
您最近一年使用:0次
解题方法
8 . 下列各式正确的是( )
A.![]() |
B.![]() |
C.![]() |
D.![]() |
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9 . 若
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38dd8aad9cfb5e1fe2a45d80923f1571.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/046387911745f43ff3b6804ea58eb26a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d718077f631a1509ada814ab784c8087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38dd8aad9cfb5e1fe2a45d80923f1571.png)
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10 . 已知
中,角A,B,C对应边分别为a,b,c.
(1)求证:
;
(2)已知
.
①若
,求A;
②若
是锐角三角形,且
,求
周长的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8df60d8ae1e87ccc51be55f99b01f3b9.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b19988d792b5252222f0a7acf7ef5fd.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3578b63c5903089595bf324c809a997c.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次