已知等比数列{an}中,a4a5=9,则log3 a1+log3 a2+...+log3 a8=_____._数学解答

已知等比数列{an}中,a4a5=9,则log3 a1+log3 a2+...+log3 a8=_____.

人气：363 ℃　时间：2020-02-05 13:14:25

解答

log3 a1+log3 a2+...+log3 a8
=log3[a1a2...a8]
=log3[(a1a8)(a2a7)..(a4a5)]
=log3[9^4)
=log3(3^8)
=8