解题方法
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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2 . 数学中有各式各样富含诗意的曲线,螺旋线就是其中比较特别的一类.螺旋线这个名词来源于希腊文,它的原意是“旋卷”或“缠卷”.小明对螺旋线有着浓厚的兴趣,用以下方法画出了如图所示的螺旋线.具体作法是:先作边长为1的正三角形ABC,分别记射线AC,BA,CB为
,
,
,以C为圆心、CB为半径作劣弧
交
于点
;以A为圆心、
为半径作劣弧
交
于点
;以B为圆心、
为半径作劣弧
交
于点
,依此规律,就得到了一系列圆弧形成的螺旋线.记劣弧
的长,劣弧
的长,劣弧
的长,…依次为
,
,
,…,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a004bc7c90ab090e76a37d3a4c58fb3.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9fce9427c9b17e4d3cda0c3ff3e2e14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cabc3303519ac16fc998913ad9f349c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b7d857811cbd619f868d951aa7a0ab8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9fce9427c9b17e4d3cda0c3ff3e2e14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cabc3303519ac16fc998913ad9f349c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a004bc7c90ab090e76a37d3a4c58fb3.png)
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名校
解题方法
3 . (多选)古代中国的太极八卦图是以同圆内的圆心为界,画出相等的两个阴阳鱼,阳鱼的头部有阴眼,阴鱼的头部有个阳眼,表示万物都在相互转化,互相渗透,阴中有阳,阳中有阴,阴阳相合,相生相克,蕴含现代哲学中的矛盾对立统一规律.图2(正八边形
)是由图1(八卦模型图)抽象而得到,并建立如下平面直角坐标系,设
.则下述四个结论,正确结论是( )
![](https://img.xkw.com/dksih/QBM/2021/1/6/2630461899374592/2633188182204416/STEM/a3bd39b9-222a-4261-992f-9dac4e8697b8.png?resizew=448)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d17d4a6cf11cda87b3dfafaecdec683f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52705567101a48893de582656ef41527.png)
![](https://img.xkw.com/dksih/QBM/2021/1/6/2630461899374592/2633188182204416/STEM/a3bd39b9-222a-4261-992f-9dac4e8697b8.png?resizew=448)
A.以直线![]() ![]() |
B.在以点![]() ![]() ![]() ![]() |
C.![]() |
D.![]() |
您最近一年使用:0次
2021-01-10更新
|
351次组卷
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2卷引用:重庆市铜梁区铜梁中学2021届高三上学期半期考试数学试题