a2a4a8的知识精选

已知等差数列{an}的公差和首项都不为零,且a2,a4,a8成等比数列,则=(  )A.           ...
问题详情:已知等差数列{an}的公差和首项都不为零,且a2,a4,a8成等比数列,则=()A.              B.           C.           D.2【回答】 B解析设等差数列的首项为a1,公差为d,则a2...
已知等差数列{an}的公差和首项都不等于0,且a2,a4,a8成等比数列,则=(  )A.2         ...
问题详情:已知等差数列{an}的公差和首项都不等于0,且a2,a4,a8成等比数列,则=()A.2              B.3           C.5              D.7【回答】B由题意,得=a2a8,∴(a1+3d)2=(a1...
热门标签