名校
解题方法
1 . (1)如图,在矩形ABCD中,
,E为AB的中点,F是BC边上靠近点B的三等分点,AF与DE于点G.求
的余弦值;
(2)利用本学期所学知识(向量或解三角形)证明:平行四边形的两条对角线长的平方之和等于四条边长的平方之和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ecaea23c77bf54da0efcf95c463f0bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7d6902c8862bd2616be038549f77aff.png)
(2)利用本学期所学知识(向量或解三角形)证明:平行四边形的两条对角线长的平方之和等于四条边长的平方之和.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/8/91f6f1fe-5465-4e7f-b754-3b346a2cb81f.png?resizew=113)
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2 . 结合下面的阅读材料,研究下面两个问题.
(1)一个三角形能否具有以下两个性质(i)三边是连续的三个偶数,(i)最大角是最小角的2倍;
(2)一个三角形能否具有以下两个性质(i)三边是连续的三个奇数,(i)最大角是最小角的2倍.
阅读材料:习题(人教版必修5第一章复习参考题B组3)研究一下,一个三角形能否具有以下性质:
(1)三边是连续的三个自然数;(2)最大角是最小角的2倍.
解:(方法一)设三角形三边长分别是
,
,
,三个角分别是
,
,
,
由正弦定理,
,所以
:
由余弦定理,
,
所以
,
化简得
,
所以![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfd09fb9482124fd35f19b86894648f4.png)
三角形的三边分别是
,可以验证此三角形的最大角是最小角的
倍.
(方法二)先考虑三角形所具有的第一个性质:三边是连续的三个自然数,
(1)三边长不可能是
这是因为
,与三角形任何两边之和大于第三边;
(1)一个三角形能否具有以下两个性质(i)三边是连续的三个偶数,(i)最大角是最小角的2倍;
(2)一个三角形能否具有以下两个性质(i)三边是连续的三个奇数,(i)最大角是最小角的2倍.
阅读材料:习题(人教版必修5第一章复习参考题B组3)研究一下,一个三角形能否具有以下性质:
(1)三边是连续的三个自然数;(2)最大角是最小角的2倍.
解:(方法一)设三角形三边长分别是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5aadf9ab510510120699c5eee39ab18b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a0876215b2fd463d151523cd3c6b447.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82609af153365dcdc4ab64825a142b02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8dd0c52aca1675c17b9a019aa7901e3.png)
由正弦定理,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1572cc4e88c14f0c537360a368b7f423.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9a1597f3620ec4630526e663673aed2.png)
由余弦定理,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a6fef75950bf476a5f93737533b2e32.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b3b4d15402a44f99d247abe944d06ff.png)
化简得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acb623784578945deb88ec4a6acbca3e.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfd09fb9482124fd35f19b86894648f4.png)
三角形的三边分别是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f734712e39d68a541159bf61d865ba69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
(方法二)先考虑三角形所具有的第一个性质:三边是连续的三个自然数,
(1)三边长不可能是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c73d43981283ac63dbc0d1cfc7426d83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdc114012e9d5888ca8ac6b6eacd306e.png)
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名校
解题方法
3 . 某校学生利用解三角形有关知识进行数学实践活动.
处有一栋大楼,某学生选
、
(与
在同一水平面上)两处作为测量点,测得
的距离为
,
,
,在
处测得大楼(大楼
与水平面
垂直)楼顶
的仰角
为
.
两点间的距离;
(2)求大楼的高度及二面角
的正切值.
![](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/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c56c87fd6bf8a44244ba51a9d244e22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c42ed2e5bd5a0f033e24008697bf4963.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d0ec7f8ab857cd441a82389b246230a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098a3e7d1f1890863b7483a98b618119.png)
(2)求大楼的高度及二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab6d47edbcc2ae6efcfd7f28e401e3e9.png)
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名校
4 . 已知
.
(1)求函数
的单调增区间;
(2)设方程
在
上的两解为
和
,求
的值;
(3)在
中,角
的对边分别为
.若
,
,且
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6701e02c0045f484f370875a6e26face.png)
(1)求函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
(2)设方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb381ac86308c6249bc7e8737cdc668d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5027c72c679bd6407806ca2805cbdd49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59e6dee75c5151241be17548a1d9295e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5438613cda89232a531a69da49dee747.png)
(3)在
![](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/2bd5b9bbd3d22bd2cef53dd4b9691257.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b22e4c9f482aee8735f3c38bdbe70402.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34af8c11f3649b7ac3f3c7c346a5915d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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名校
解题方法
5 . 已知
的内解
所对的边分别为
,满足
.
(1)求证:
;
(2)若
为
上一点,且
,求
的面积的最大值.
![](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/1db789b3e162dc967f1fb1dc58a988fa.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baa8d75a6638e08eedbff8662267da6f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df01d40611ad128b314244ac8090cd95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
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2023-07-16更新
|
541次组卷
|
2卷引用:福建省厦门市2022-2023学年高一下学期期末质量检测数学试题
6 . 给出以下条件:①
;②
;③
.请在这三个条件中任选一个,补充在下面的问题中并作答.
问题:在
中,角A,B,C所对的边分别为a,b,c,且__________.
(1)求角B的大小;
(2)已知
,且角A只有一解,求b的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6940feefeabe6725c61f13177fb96ad7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf31bfc4f60f6b0da8d8f57f39f2c3c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e719f6a30e8bc743d821655b7a85d0a0.png)
问题:在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(1)求角B的大小;
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3d441ddca6d9972549b35d21082728a.png)
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7 . 记
的内角A,B,C的对边分别为a,b,c.已知
,
,
,求角B时,解的情况是( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b86d43790babcdbbdc03493ee70928.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab839d8569171afab5ed55c22013aa72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82986ab38a4ae58593191ccae2a44f62.png)
A.无解 | B.一解 | C.两解 | D.无数解 |
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名校
解题方法
8 . 某校学生利用解三角形有关知识进行数学实践活动.
处有一栋大楼,某学生选
,
两处作为测量点,测得
的距离为
,
,
,在
处测得大楼楼顶
的仰角
为75°.
两点间的距离;
(2)求大楼的高度.
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c56c87fd6bf8a44244ba51a9d244e22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c42ed2e5bd5a0f033e24008697bf4963.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d0ec7f8ab857cd441a82389b246230a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(2)求大楼的高度.
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2023-04-21更新
|
1528次组卷
|
8卷引用:宁夏吴忠市吴忠中学2022-2023学年高一下学期数学期末考试练习试题
名校
解题方法
9 . 下列说法中正确的是( )
A.若![]() ![]() ![]() ![]() |
B.在![]() ![]() ![]() |
C.两个不能到达的点之间无法求两点间的距离 |
D.在![]() ![]() |
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2021-09-17更新
|
1645次组卷
|
5卷引用:安徽省滁州市定远县民族中学2022-2023学年高一下学期数学期末试卷
安徽省滁州市定远县民族中学2022-2023学年高一下学期数学期末试卷河北省张家口市第一中学2020-2021学年高一下学期期中数学试题(已下线)11.3 余弦定理、正弦定理的应用-2021-2022学年高一数学10分钟课前预习练(苏教版2019必修第二册)(已下线)第6章 平面向量及其应用(典型30题专练)-2021-2022学年高一数学考试满分全攻略(人教A版2019必修第二册)(已下线)山东省潍坊市2022-2023学年高二上学期开学检测数学试题
解题方法
10 . 在
中,角
所对应的边分别为
,
,
时,
(1)若
,求![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
(2)记![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42aba8f1886711e2777cb745c7bfdf1e.png)
(i)当
为何值时,使得
有解;(写出满足条件的所有
的值)
(ii)当
为何值时,
为直角三角形
(iii)直接写出一个满足条件的
值,使得
有两解
![](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/23725094c363fd158166a8698971694c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e899c486dc49e560fc4aca05e16835b7.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f34365e5040ce6944115c8da61bf110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42aba8f1886711e2777cb745c7bfdf1e.png)
(i)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(ii)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(iii)直接写出一个满足条件的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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