已知等比数列an,首项为81,数列bn满足bn=log3an,其前n项和sn(1)证明：bn-b(n-1)=log(3)an-log(3)an-1=log（3）an/a(n-1)=log(3)q∵b1=log(3)81=4∴数列﹛bn﹜是以4为首项,公比为log(3)q的等差数列.(2)若s11≠s12,且s1...