发布时间：2021-02-21 07:53:03
(本小题满分12分) 已知函数，数列，满足条件：．
（1）求证：数列为等比数列；
（2）令，Tn是数列的前n项和，求使成立的最小的n值．
解：(1) 证明：由题意得，
∴ ········································································ 3分
又 ∵
∴ ················································································ 4分
故数列{bn +1}是以1为首项，2为公比的等比数列·············································· 5分
(2) 由 (1) 可知，，∴ ·········································· 7分
故················································ 9分
∴
············································ 10分
由，得
∴ 满足条件的n的最小值为10···································································· 12分
【解析】略