【简答题】(本小题满分10分) 选修4-4:坐标系与参数方程选讲 已知曲线 的参数方程为 ( 为参数),曲线 的参数方程为 ( 为参数). (1)若将曲线 与 上各点的横坐标都缩短为原来的一半,分别得到曲线 和 ,求出曲线 和 的普通方程; (2)以坐标原点为极点, 轴的非负半轴为极轴建立极坐标系,求过极点且与 垂直 的直线的极坐标方程.
【简答题】Why was the League superseded by the UN?
【单选题】Why was the UN divided into distinct bodies?
A.
To protect the rights of small nations.
C.
To serve different functions.
D.
To serve for different chairmen.
【简答题】在平面直角坐标系 中,曲线 的参数方程为 ( 为参数),曲线 的参数方程为 ( 为参数).在以 为极点, 轴的正半轴为极轴的极坐标系中,射线 与 , 各有一个交点.当 时,这两个交点间的距离为 ,当 时,这两个交点重合. (Ⅰ)分别说明 , 是什么曲线,并求出a与b的值; (Ⅱ)设当 时, 与 , 的交点分别为 ,当 时, 与 , 的交点分别为 ,求四边形 的面积.
【简答题】(坐标系与参数方程选做题) 已知曲线 的参数方程为 ( 为参数),曲线 的参数方程为 ( 为参数),则两条曲线的交点是
【单选题】Why was Douglas called the 'Little Giant'?
A.
Because he felt strongly about slavery.
B.
Because he was defeated by Lincoln for President.
C.
Because he was short in stature but strong in frame.
D.
Because his head was larger than his shoulders.