如图,用两根绳子牵引重为
的物体,两根绳子的拉力分别为
,
,此时平衡.如果
,
与
的夹角
.
的大小(精确到1N);
(2)求
与
的夹角
的值(精确到0.1°).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb0a7565dbb8e665bb691d1de0c73675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1282962a17a48a18edf733204054d67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6773de8f14f06da06bf9c6f22738c6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1282962a17a48a18edf733204054d67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3bea7383acbd1da6d0d5f10ef1b2aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1282962a17a48a18edf733204054d67.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1282962a17a48a18edf733204054d67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5076289823db419f94e9c0c8f4aafd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
20-21高一·全国·课后作业 查看更多[3]
更新时间:2021-11-12 17:40:42
|
相似题推荐
解答题-问答题
|
较易
(0.85)
名校
解题方法
【推荐1】已知四边形
的外接圆面积为
,且
为钝角,
(1)求
和
;
(2)若
,求四边形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50167609e264c9669adaa4f4a23cc092.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cabd72426604c62b916ef965bae818eb.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50a399506a23c405d72321775dcf4489.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
解题方法
【推荐2】设△ABC的内角A,B,C的所对边分别为a,b,c,已知sin2(B+C)=sin2B﹣sinBsinC+sin2C.
(1)求cosA;
(2)若c=
,求sinC.
(1)求cosA;
(2)若c=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7aa85bfb514b73c6f994d2fa54e29f7.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
名校
【推荐1】如图,某大型厂区有三个值班室
,值班室
在值班室
的正北方向
千米处,值班室
在值班室
的正东方向
千米处.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/92897bd9-0c46-43ad-a940-73f746da642a.png?resizew=161)
(1)保安甲沿
从值班室
出发行至点
处,此时
千米,求
的距离,并说明点
在点
方向角哪个方向上;
(2)保安甲沿
从值班室
出发前往值班室
,保安乙沿
从值班室
出发前往值班室
,甲乙同时出发,甲的速度为
千米/小时,乙的速度为
千米/小时. 若甲乙两人通过对讲机联系,对讲机在厂区内的最大通话距离为
千米(含
千米),试问有多长时间两人不能通话?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.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/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/92897bd9-0c46-43ad-a940-73f746da642a.png?resizew=161)
(1)保安甲沿
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be41b05e11ba5eadaaed9a224b949774.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)保安甲沿
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.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/f52a58fbaf4fea03567e88a9f0f6e37e.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/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
名校
解题方法
【推荐2】已知在
中,内角A,B,C的对边分别为a,b,c,满足
.
![](https://img.xkw.com/dksih/QBM/2022/3/1/2926877560168448/2930230832766976/STEM/803d4921-1ff1-4492-af35-7cd1c3ae7546.png?resizew=137)
(1)求B;
(2)如图,若
,在
外取点D.且
,
.求四边形ABCD面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcfb88fd450f5e11bcdd5642ed9f9ea6.png)
![](https://img.xkw.com/dksih/QBM/2022/3/1/2926877560168448/2930230832766976/STEM/803d4921-1ff1-4492-af35-7cd1c3ae7546.png?resizew=137)
(1)求B;
(2)如图,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d783fe7f3ce673d5d21281174e7a7968.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037b342a682cbd4241855a243da3c016.png)
您最近一年使用:0次