二项式(x+12x)n展开式中的前三项系数成等差数列，则n的值为______． 发布时间：2017-04-29 01:18 │ 来源：www.tikuol.com 题型：填空题 问题： 二项式(x+12x)n展开式中的前三项系数成等差数列，则n的值为______．
题型：填空题 把函数y=sinx（x∈R）的图象上所有点向左平行移动π3个单位长度，再把所得图象上所有点的横坐标缩短到原来的12倍（纵坐标不变），得到的图象所表示的函数是（ ）A．y=sin(2x-π3)，x∈RB．y=sin(x2+π6)，x∈RC．y=sin(2x+π3)，x∈RD．y=sin(2x+2π3)，x∈R 查看答案
题型：填空题 ---What _________ to the building? ---It _________ when all the people were sleeping. A．has happened; was broken inB．was happening; was broken down C．was happened; broke into D．happened; was broken into 查看答案