【单选题】将函数y=sin2x的图象上所有的点向右平行移动 π 8 个单位长度,再把所得各点的横坐标缩短到原来的 1 2 倍(纵坐标不变),则所得函数的图象( )
【单选题】Why did the accident take place? Because ______.
A.
the doctor drove badly
【简答题】(本题满分7分)如图,在平面直角坐标系中,△ ABC的三个顶点的坐标分别为A(0,1),B(-1,1),C(-1,3)。 小题1:(1)画出△ABC关于x轴对称的△A 1 B 1 C 1 ,并写出点C 1 的坐标; 小题2:(2)画出△ABC绕原点O顺时针方向旋转90°后得到的△A 2 B 2 C 2 ,并写出点C 2 的坐标;, 小题3:(3)将△A 2 B 2 C 2 平移得到△ A 3 B ...
【单选题】在污水的药剂中和法中,最常用的药剂是( )。
【单选题】The general election, originally ______for 29thSeptember, is to bepostponed until December.
【单选题】在污水的药剂中和法中,最常用的药剂是()
【单选题】Why did one Westlake teacher say they are giving students 'a window to the world'?
A.
Because students can attend lectures on information technology in Westlake college.
B.
Because students can travel around the world by the laptops there.
C.
Because students can get information from around the world by the laptops there.
D.
Because students Can have free laptops in Westlake college.
【单选题】Why did many southerners go to the Northeast and the Midwest during World, War Ⅱ?
A.
They wanted to learn to like country music.
B.
They wanted to take music with them.
C.
Country music was popular all over the country.
D.
They wanted to work in the factories there.
【简答题】在平面直角坐标系内有两个定点F 1 ,F 2 和动点P,F 1 ,F 2 坐标分别为F 1 (-1,0)、F 2 (1,0),动点P满足 | PF 1 | | PF 2 | = 2 2 ,动点P的轨迹为曲线C,曲线C关于直线y=x的对称曲线为曲线C″,直线y=x+m-3与曲线C″交于A、B两点,O是坐标原点,△ABO的面积为 7 , (1)求曲线C的方程; (2)求m的值.