等比数列{an}中的各项均为正数,且a5a6+a4a7=18,则log3a1+log3a2+...+log3a10=
人气:316 ℃ 时间:2020-03-23 06:58:28
解答
由于{an}为等比数列则:a5a6=a4a7=a3a8=a2a9=a1a10又a5a6+a4a7=18则:2a5a6=18a5a6=9则:log3(a1)+log3(a2)+...+log3(a9)+log3(a10)=log3[a1*a2*a3*...*a10]=log3[(a1a10)*(a2a9)*...*(a5a6)]=log3[9*9*...*9]=log3[9^5...
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