已知数列{a n },a n =p n +λq n (p>0,q>0,p≠q,λ∈R,λ≠0,n∈N*). (1)求证:数列{a n+1 -pa n }为等比数列; (2)数列{a n }中,是否存在连续的三项,这三项构成等比数列?试说明理由; (3)设A={(n,b n )|b n =3 n +k n ,n∈N*},其中k为常数,且k∈N * ,B={(n,c n )|c n =5 n ,n∈N*},求A∩B.
【简答题】SECTION A TALK In this section you will hear a talk. You will hear the talk ONCE ONLY. While listening, you may look at the task on ANSWER SHEET ONE and write NO MORE THAN THREE WORDS for each gap. Ma...