名校
解题方法
1 .
中,a,b,c分别是内角A、B、C的对边,已知
,
,现有以下判断:
①若
,则B有两解;
②b+c不可能等于12;
③若
,则
的面积为
;
④
的最大值为
.
请将所有正确的判断序号写在横线上______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99f2f1eb2beb23690f56a68dc7da08cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f08ce80e91fdf435a8e3ec05be990e9d.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5742b2684d00be50a66e01c9acb6b51f.png)
②b+c不可能等于12;
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5eeefa3c7678900a6aabec118757db8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b27567d43c5b91382ee3d7ca708ee422.png)
④
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c7c566e3d65ca9c450d47980b7e66ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/427cc3ae2dab5580fcb93eba22246595.png)
请将所有正确的判断序号写在横线上
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2 . 中国古代数学名著《九章算术•商功》中,阐述:“斜解立方,得两堵.斜解壍堵,一为鳖臑.阳马居二,鳖臑居一”,
平面ABC,
,PA=AB=BC=4,则PB与AC所成的角等于______ ;PC与AB之间的距离等于______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://img.xkw.com/dksih/QBM/2021/10/21/2834324322140160/2834895242723328/STEM/03c7391e49664728926e4b1399819c8e.png?resizew=128)
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3 . 有一解三角形的题,因纸团破损有一个条件不清,具体如下:在
中,已知
,
,__________ 求角
经推断破损处的条件为三角形一边的长度,且答案提示
,试将条件补充完整.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8120119749d4bc28067e73fca7d46cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dd7dd92ecaa6d218ee984b4be92b115.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0ebd06e89654d96d8a7b44905e89e38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99f2f1eb2beb23690f56a68dc7da08cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
您最近一年使用:0次
2021-08-15更新
|
596次组卷
|
3卷引用:北京市第二十五中学2021-2022学年高一下学期期中数学试题
4 . 已知函数
.
(1)求
,
;
(2)求
在区间
上的最大值和零点.
解:(1)求
______;
______;
(2)因为
,所以
,
所以当
______;即
______时,
取得最大值,为______;
由
和
得
,
,
所以
在区间
上的零点为______.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e700a7374e42cf71db7c7b2ded5cd2df.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d62ddbb913432ea8d72ecf7fa38f7c35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ecd5f251e8a94a611cc98d239ff9575.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c993caf22cc0a9d3834daa57d07695c7.png)
解:(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a7cca5e50ce06e7c0e7effee4b5167a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5a2758a8127e14b5e5357ec19a3f920.png)
(2)因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d01282e80562ddbb74f7207ae04794e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cb3cc36c5ee55457a8fb6d1335d4e76.png)
所以当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/649b00ea05d7fa901d162d61abc5e2fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
由
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86b92b70365c63607daecdc8deb73ecf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cb3cc36c5ee55457a8fb6d1335d4e76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a27e065e1eb081abb94488daff61a77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb2133a8576a013055f8fab50f52c215.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c993caf22cc0a9d3834daa57d07695c7.png)
空格序号 | 选项 |
① | A.![]() ![]() |
② | A.![]() B. ![]() |
③ | A.![]() ![]() ![]() ![]() |
④ | A.1 B.![]() |
⑤ | A.![]() ![]() |
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