【简答题】已知数列a n ,其前n项和为 S n = 3 2 n 2 + 7 2 n? (n∈ N * ) . (Ⅰ)求数列a n 的通项公式,并证明数列a n 是等差数列; (Ⅱ)如果数列b n 满足a n =log 2 b n ,请证明数列b n 是等比数列,并求其前n项和; (Ⅲ)设 c n = 9 (2 a n -7)(2 a n -1) ,数列{c n }的前n项和为T n ,求使不等式T n >...
【简答题】听句子,选图片。 ( )1. What's this? ( )2. What does Tom play every day? ( )3. Where is the alarm? ( )4. Which picture is right(对的)? ( )5. What is the man talking about (谈论)?