反证法与放缩法
1.A=1+++...+与(n∈N+)的大小关系是________.
2.已知a>2,则loga(a-1)loga(a+1)________1(填">"、"<"或"=").
3.已知0 4.已知数列{an}满足a1=2,an+1=22·an(n∈N+), (1)求a2,a3并求数列{an}的通项公式; (2)设cn=,求证:c1+c2+c3+...+cn<.
4.已知数列{an}满足a1=2,an+1=22·an(n∈N+),
(1)求a2,a3并求数列{an}的通项公式;
(2)设cn=,求证:c1+c2+c3+...+cn<.