数学中有许多形状优美、寓意美好的曲线,如星形线(如图),若让一个半径为
的圆在一个半径为
的圆内部,沿着圆的圆周滚动,小圆圆周上的任一点形成的轨迹即为星形线,其方程为
,给出下列四个结论,正确的有( )
![](https://img.xkw.com/dksih/QBM/2021/1/23/2642242996936704/2651074466897920/STEM/c29be142c2fb4e608f4708b4cea1ede7.png?resizew=175)
(1)星形线的参数方程为:
(
为参数)
(2)若
,则星形线及其内部包含33个整点;(即横、纵坐标均为整数的点)
(3)曲线
在星形线
的内部(包含边界);
(4)设星形线围成的面积为
,则
;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b7081727a19eba3003a689f78872086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/309ad39777b3791c60c6c2782fd1e41f.png)
![](https://img.xkw.com/dksih/QBM/2021/1/23/2642242996936704/2651074466897920/STEM/c29be142c2fb4e608f4708b4cea1ede7.png?resizew=175)
(1)星形线的参数方程为:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ba98a3cbae70b69aaa45d034f358b9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab839d8569171afab5ed55c22013aa72.png)
(3)曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaceba4bfaac6c7a6dff561d92d9096a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bb228a835eea0494d4422a42e77dd69.png)
(4)设星形线围成的面积为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d53b0f9c28ab94f1f6c1db3766b6b88b.png)
A.(1)(3)(4) | B.(1)(2)(3)(4) |
C.(2)(3) | D.(1)(2)(3) |
20-21高二上·上海徐汇·期末 查看更多[3]
更新时间:2021-02-04 23:27:43
|
【知识点】 普通方程化为参数方程解读