關於4T9的百科

• 等比數列{an}是遞減數列,其前n項的積爲Tn,若T13＝4T9,則a8·a15等於(   )A.±2    ...

• 問題詳情：等比數列{an}是遞減數列,其前n項的積爲Tn,若T13＝4T9,則a8·a15等於(   )A.±2                 B.±4                 C.2                     D.4【回答】解析:∵{an}是遞減數列,則a1＞0,0＜q＜1或a1＜0,q＞1...
• 2022-08-1817733