1 . 设
的内角
的对边分别为
,
,且
为钝角.
(1)求
;
(2)证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.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/4411d1fbc9d0ab49db36a9e71c536fbc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06430886275f5ad62bcda62fce691e99.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/760cd6d09c8a1302e45d825f9594e6f3.png)
您最近一年使用:0次
名校
解题方法
2 . 在
中,
,点
在
边上,且
.
(1)求角
的大小;
(2)若
为
的中线,且
,求
的长;
(3)若
为
的高,且
,求证:
为等边三角形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07160f14b3b453bebb64cb2bf96dc85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8aad9ebd0129196545231e95fd6ef521.png)
(1)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e1f4f255d191786f7d330d278868c2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4187a861d1c558ee70701fc501f58842.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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3 . 求证:在△ABC中,有
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bf190a17c183d19606dafe0f557ea1.png)
您最近一年使用:0次
2020-01-30更新
|
382次组卷
|
6卷引用:人教B版(2019) 必修第四册 逆袭之路 第九章 9.1.2 余弦定理(1)
人教B版(2019) 必修第四册 逆袭之路 第九章 9.1.2 余弦定理(1)(已下线)【新教材精创】9.1.2 余弦定理(第2课时)导学案(1)(已下线)11.3 余弦定理、正弦定理的应用人教B版(2019)必修第四册课本习题9.1.2 余弦定理苏教版(2019)必修第二册课本习题 习题11.3(已下线)第九章 解三角形 9.1 正弦定理与余弦定理 9.1.2 余弦定理
名校
解题方法
4 . 在
中,角
,
,
所对的边分别为
,
,
,且
.
(1)求证:
;
(2)若
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.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/f296989add06c4bc2207a20b0746e533.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ff7989c371fc6dd1627bdb88fcb917d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7b9446d7b31f0d6e044cf99deeb20aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5201fc26d013f6fb889933c0e32f5c53.png)
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解题方法
5 . 已知
中,角
,
,
的对边分别为
,
,
,且满足
,
,
(Ⅰ)求证:
;
(Ⅱ)若边
上中线
,求
的面积.
![](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/23882269b69a55c4227f006a7ad0b37c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be8819cc94366a9931d38af58ac6d7e3.png)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7f85678de64dcc06b3efcdb6a127170.png)
(Ⅱ)若边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2395720e6d6aeb7efdcd8e921849acf4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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6 . 通常用
分别表示△ABC的三个内角A、B、C所对的边的长度,R表示△ABC外接圆半径.
(1)在以O为圆心,半径为2的圆O中,BC和BA是圆O的弦,其中BC=2,∠ABC=45°,求弦AB的长;
(2)在△ABC中,若∠C是钝角,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7f5573b30734d65648f61c0a94c98de.png)
(1)在以O为圆心,半径为2的圆O中,BC和BA是圆O的弦,其中BC=2,∠ABC=45°,求弦AB的长;
(2)在△ABC中,若∠C是钝角,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/367961102740219545901df94d226ad2.png)
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7 .
的内角的对边
分别为
.
(1)求证:
;
(2)在边
上取一点P,若
.求证:
.
![](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)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52bd9362c24922a2a3af255fac9bbfe2.png)
(2)在边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad46f23c0313f49d9bc1fec0e9641612.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c8580839def5eb012fce630d4fa50eb.png)
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8 . 证明三角形
的面积公式
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d7990ee0a6f7bb09543e3abd1202b76.png)
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2020-02-03更新
|
304次组卷
|
2卷引用:人教A版(2019) 必修第二册 逆袭之路 第六章 6.4 平面向量的应用 小结
名校
9 . 在
中,
、
、
分别为角
、
、
的对边,若
.
(1)判断
的形状,并证明;
(2)若
,
,
为满足题设条件的所有
中线段
上任意一点(可与端点重合),求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.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/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/787ec876d59cc33b33faf0c31abe6430.png)
(1)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4580cc037c0c760c728cdbb74a8154c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b939d7f28b83c87639ae58f306aee021.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff72ed78e49ce4888bbfd8d0a8d3e476.png)
您最近一年使用:0次
2019-12-06更新
|
1027次组卷
|
2卷引用:重庆市第一中学2018-2019学年高一下学期4月月考数学试题
10 . 在
中,角
所对的边分别为
.
(1)若
为
边的中点,求证:
;
(2)若
,求
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38335830b93ac4d99c28a8e209eecb3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7f5573b30734d65648f61c0a94c98de.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea49e8abfc92cb54c73539c09541309b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79017fd0fd57bdc170b917b4e20f4c0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
您最近一年使用:0次