来自全立新的问题
已知等差数列{an},a1+a3+a5=42,a4+a6+a8=69;等比数列{bn},b1=2,log2(b1b2b3)=6.(Ⅰ)求数列{an}和数列{bn}的通项公式;(Ⅱ)设cn=an-bn,求数列{|cn|}的前n项和Tn.
已知等差数列{an},a1+a3+a5=42,a4+a6+a8=69;等比数列{bn},b1=2,log2(b1b2b3)=6.
(Ⅰ)求数列{an}和数列{bn}的通项公式;
(Ⅱ)设cn=an-bn,求数列{|cn|}的前n项和Tn.
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2020-11-18 02:19