1 . 证明:
(1)
.
(2)已知
,
,求证:
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1fc2d308d990e5771657c9f56a0936b.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fbdc8633a22f3b9fb3a789d3818657a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45a173784888adf2946382fa093ba53a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/129f958b08c51df454111d41c6db204f.png)
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2 . 已知
的三边
,
,
成等差数列.
(1)求证:
;
(2)若
不是等边三角形,证明其三边
,
,
的倒数不成等差数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65cf6a68b7a0e5458c9c816404f71ff9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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)
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3 . (1)请直接运用任意角的三角比定义证明:
;
(2)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75cd397c31481b526bba6136f925b29d.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5417c231457711c7436efc826c66b45a.png)
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4 . 已知三角形
中,角A,B,C所对边分别为a,b,c,
.
(1)求证:角B为钝角;
(2)若
,
,求三角形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b094f28f5591b0932402ab8d0e93a14.png)
(1)求证:角B为钝角;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7806bf3865558f820a9bace47198fc41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49c13034e0263468ba75ad1705cd57b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
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5 . 17世纪法国数学家费马在给朋友的一封信中曾提出一个关于三角形的有趣问题:在三角形所在平面内,求一点,使它到三角形每个顶点的距离之和最小.现已证明:在
中,若三个内角均小于120°,则当点
满足
时,点
到
三个顶点的距离之和最小,点
被人们称为费马点.根据以上知识,已知在
中,
,
,
,
为
内一点,则
的最小值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc3229917a0b4d72138d3c05725c1d9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f08273d339dc5ddbb89aa67bb8205e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07160f14b3b453bebb64cb2bf96dc85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/263385aa0b73a4429f9b652f7fa6dc5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a45d458ce755deae9c15645993f6db65.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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6 . 已知
中,角
所对的边分别为
,且
.
(1)证明:
;
(2)若
,求角
的大小.
![](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/2d30c09654f245ee4173a89352de0d0a.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65c875691cec70bedee102d280f2f31.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1101850aa60cb0051fa2fb765ed064e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
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7 . 化简与证明:
(1)![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13e01d46f19502dcb7293ad7b02757b7.png)
(2)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13e01d46f19502dcb7293ad7b02757b7.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a0658e17f7857d2334934d62687974a.png)
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8 . 数学里有一种证明方法叫做Proofwithoutwords,也被称为无字证明,是指仅用图象而无需文字解释就能不证自明的数学命题,由于这种证明方法的特殊性,无字证明被认为比严格的数学证明更为优雅与有条理.如下图,点
为半圆
上一点,
,垂足为
,记
,则由
可以直接证明的三角函数公式是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d55963a9b9b02737110f57a377b41cb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/813b1b0327154103afd7a728f00cfeda.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd7192893cff0c527c586d7d45f6dccf.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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9 . “弦图”是我国古代三国时期的数学家赵爽为《周髀算经》作注时为证明勾股定理所绘制,此图曾作为2002年在北京召开的第24届国际数学家大会的会标如图,在正方形
中,有4个全等的直角三角形,若图中
的两锐角分别为
,且小正方形与大正方形的面积之比为
,则
的值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20594870f716ac46c23b8bc7df61a053.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e288596fa3811dd2c17bded60e82e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/955bed8cd82419dbb2c62550ee494677.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22d521f8d021b20757d7a68107fcef1d.png)
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10 . 求证:
(1)
;
(2)
;
(3)
.
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5ab2a2cc9cac678396335f139b5e4e2.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe296b3307ee91663898ecf076d08eb9.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3518ac824ae7d8a702a7957458f94e9.png)
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2023-10-09更新
|
823次组卷
|
11卷引用:北师大版(2019)必修第二册课本习题第四章1.3综合应用
北师大版(2019)必修第二册课本习题第四章1.3综合应用(已下线)专题5.2 三角函数的概念-举一反三系列(已下线)模块二 专题4《三角函数的概念》单元检测篇 A基础卷 (人教A)(已下线)5.2.2 同角三角函数的基本关系(5大题型)精练-【题型分类归纳】(人教A版2019必修第一册)(已下线)5.2 三角函数概念(AB 分层训练)-【冲刺满分】7.2 三角函数概念(2)-【帮课堂】(苏教版2019必修第一册)(已下线)考点2 同角三角函数基本关系式的应用 --2024届高考数学考点总动员【练】(已下线)5.2.2同角三角函数基本关系(第2课时)(已下线)7.2.3 同角三角函数的基本关系式-【帮课堂】(人教B版2019必修第三册)(已下线)1.3 综合应用北师大版(2019)必修第二册课本例题1.3 综合应用