皮皮学，免费搜题
登录
搜题
【简答题】
已知数列{a n } 满足a n =2a n-1 +2 n -1（n∈N * ，n≥2），且a 4 =81 （1）求数列的前三项a 1 、a 2 、a 3 的值； （2）是否存在一个实数λ，使得数列 { a n +λ 2 n } 为等差数列？若存在，求出λ的值；若不存在，说明理由；求数列a n 通项公式．
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【简答题】Piece by piece, she developed a picture of his escape: Harry was on 87 when the plane hit. He stopped to help on 78. He met up with Hong on 53 . But as hard as she tried, as many questions a s she ask...
【简答题】根据Text A Unit 1内容填写: A. L1011 didn’t arrive in Atlanta at last. B. The author was deeply touched by a womanwho try to ease her daughter with gentle and firm words. C. The ht crew announced the ...
【判断题】《十三五旅游业发展规划》要求,十三五时期,要实施乡村旅游扶贫重点村环境整治行动,到2020年,完成50万贫困户“改厨,改厕,改客房,整理院落”的三改一整工程。
A.
正确
B.
错误
【判断题】《十三五旅游业发展规划》要求,“十三五”期间,要实施乡村旅游扶贫 重点村环境整治行动,到2020年,完成50万贫困户“改厨、改厕、改客房、整理院落”的三改一整工程。
A.
正确
B.
错误
【单选题】What docs he usually do after school? He usually ______
A.
docs his homework
B.
cleans his classroom
C.
plays basketball with his classmates
【判断题】《“十三五”旅游业发展规划》指出,“十三五”时期,要实施乡村旅游扶贫重点村环境政治行动,到2020年,完成50万贫困户“改厕、改客房、整理院落"的“三改一整”工程。
A.
正确
B.
错误
【简答题】A．He usually talks quietly. B．He usually assigns homework. C．He didn't teach class today. D．He noticed that the students didn't do their homework.
相关题目：
参考解析：
知识点：
题目纠错 0
发布
