题目

题型：解答题难度：一般来源：不详

已知向量，，定义
（1）求出的解析式．当时，它可以表示一个振动量，请指出其振幅，相位及初相．
（2）的图像可由的图像怎样变化得到？
（3）设时的反函数为，求的值．

答案

17．(1)
·········································································· 4分
其振幅为，相位为，初相为················································ 7分
(2) 可由图象横坐标不变，纵坐标伸长到原来的倍，再把曲线上所有的点向左平移个单位，即可得的图象．································································· 9分
(3) 由得
∵    ∴      ∴     ∴
∴·········································································· 13分

解析

略