题干

已知直线l: {x=1+
1
2
t
y=
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.
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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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