已知直线l： {x=1+12ty=32t （t为参数），曲线C1： {x=cosθy=sinθ （θ为参数）．（Ⅰ）设l与C1相交于A，B两点，求|AB|；（Ⅱ）若把曲线C1上各点的横坐标压缩为原_刷题宝

题干

已知直线l： {x=1+

1

2

ty=

3

2

t （t为参数），曲线C₁： {x=cosθy=sinθ （θ为参数）．

（Ⅰ）设l与C₁相交于A，B两点，求|AB|；

（Ⅱ）若把曲线C₁上各点的横坐标压缩为原来的

1

2

倍，纵坐标压缩为原来的

3

2

倍，得到曲线C₂，设点P是曲线C₂上的一个动点，求它到直线l的距离的最小值．

上一题下一题 0.0难度选择题更新时间:2018-03-29 06:42:01

答案(点此获取答案解析）

解：（I）l的普通方程为y= 3 （x﹣1），C₁的普通方程为x²+y²=1，

联立方程组

{

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