如图所示,
是一块边长为7米的正方形铁皮,其中
是一半径为6米的扇形,已经被腐蚀不能使用,其余部分完好可利用.工人师傅想在未被腐蚀部分截下一个有边落在
与
上的长方形铁皮
,其中
是弧
上一点.设
,长方形
的面积为
平方米.
![](https://img.xkw.com/dksih/QBM/2022/3/15/2936860440985600/2939425435033600/STEM/e093553770a2415f81a178840ec4b832.png?resizew=148)
(1)求
关于
的函数解析式;
(2)求
的最大值及此时
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e356eb31093a3f9a3d040503d473f4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/271aceb13f86a31341c1342a30c09040.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a77ce31833750a319b3c2db7837a110d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb542855a4c0c0315084556008ff60b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/271aceb13f86a31341c1342a30c09040.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://img.xkw.com/dksih/QBM/2022/3/15/2936860440985600/2939425435033600/STEM/e093553770a2415f81a178840ec4b832.png?resizew=148)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
更新时间:2022-03-19 08:59:16
|
【知识点】 三角函数在生活中的应用解读
相似题推荐
解答题-作图题
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适中
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解题方法
【推荐1】小乐所在的课外兴趣小组计划用纸板制作一个简易潜望镜模型(图一),该模型由两个相同的部件拼接粘连制成,每个部件由长方形纸板NCEM(图二)沿虚线裁剪后卷一周形成,其中长方形OCEF卷后为圆柱
的侧面.为准确画出裁前曲线,建立如图所示的以
为坐标原点的平面直角坐标系(图二),设
为裁剪曲线上的点,作
轴,垂足为
.
(1)设图二中线段OH卷后形成的圆弧
(图一)对应的圆心角为
(rad),求
与
的关系式;
(2)求裁剪曲线
的解析式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e65ac334119ccd6204402a7aba29a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8701e0cce437edc830438b4fe6277d89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59fbd9b5e5d8be69373850d7faebdaf1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/18/4236d61d-2f4c-4710-9f22-ab5b884f2f28.png?resizew=379)
(1)设图二中线段OH卷后形成的圆弧
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5111b111c0b62990a650a817dbff416d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
(2)求裁剪曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
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解答题-问答题
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名校
【推荐2】运动员小王在一个如图所示的半圆形水域
为圆心,AB是半圆的直径
进行体育训练,小王先从点A出发,沿着线段AP游泳至半圆上某点P处,再从点P沿着弧PB跑步至点B处,最后沿着线段BA骑自行车回到点A处,本次训练结束.已知
,小王游泳、跑步、骑自行车的平均速度分别为
,
,
,设
弧度.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/127556d5-5229-4c5e-ad99-ecddc83eb2c4.png?resizew=183)
(1)试将小王本次训练的时间t表示为
的函数
,并写出
的范围;
(2)请判断小王本次训练时间能否超过40分钟,并说明理由.
(参考公式:弧长
,其中r为扇形半径,
为扇形圆心角.)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd109d3cea698760b0d5edb65bd6f241.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7a1307befd43855fb40a05034384f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ecd75424b351d8ecf2a311c525c77ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ae848ea097b4bc645cba037d272be18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cffcf224220c1ba1d2ee64fb1a0ab86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb8a96c1dfc6d8bd93400e875391b37.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/127556d5-5229-4c5e-ad99-ecddc83eb2c4.png?resizew=183)
(1)试将小王本次训练的时间t表示为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0e1fdef4a4d3d14b42ba75ed1a69bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
(2)请判断小王本次训练时间能否超过40分钟,并说明理由.
(参考公式:弧长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f091917a7dedf062ea33e7f154fb4216.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
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