1 . 从①
;②
;③
, 这三个条件中任选一个, 补充在下面问题中, 并加以解答.
在
中,三边
分别是角
的对边, 若______.
(1)求C;
(2)若
,求
的面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d8447a2411972b1375712e3c28cdca6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65d983612b3c1977916dd721d3413bce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50ad4300ec11d8da30369d44a3cdf07d.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e5ba3badffe942dcfb60da88629e7b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e70100bd019ce2be544ccd266318b0bd.png)
(1)求C;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6de1d395e6c48c0676a1488a299479d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bf59f210a4f3916022847a4fd61b6ed.png)
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2 . 已知圆锥的侧面积为
,它的侧面展开图是圆心角为
的扇形,则此圆锥的高为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cf1f865bafd4a820406d336d99f8091.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0211da37e92f915e781691296578ba0.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
3 . 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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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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5 . 在锐角
中,角
,
,
的对边分别为
,
,
.若
,
,则边
上中线
的取值范围为( )
![](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/59e29b822cda1ba926e96368094fa1a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03837b3769eda7f0d3804cc5ad4a6d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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6 . 在
中,角
,
,
的对边分别是
,
,
.若
,
,
,则角
等于( )
![](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/2f002f960ec07ea229ed243e2d991d83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b903021571c1b57943a1a3274217654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
A.30° | B.45° | C.135° | D.90° |
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7 . 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)
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8 . 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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9 . 欧拉公式
(其中i为虚数单位,
)是由瑞士著名数学家欧拉创立的,该公式将指数函数的定义域扩大到复数,建立了三角函数与指数函数的关联,在复变函数论里占有非常重要的地位.被誉为数学中的“天桥”.依据欧拉公式,下列选项正确的有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e83fbbc5fbdc4887691d675a14691fa8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/388d3d213a231cccf854a29eef611d01.png)
A.![]() |
B.![]() ![]() |
C.![]() ![]() |
D.若![]() ![]() ![]() ![]() ![]() ![]() |
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解题方法
10 . 下列各式正确的是( )
A.![]() |
B.![]() |
C.![]() |
D.![]() |
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