已知log以5为底3的次方=a,log以5为底4的次方=4,用a.b表示log以25为底12的次方_数学解答

已知log以5为底3的次方=a,log以5为底4的次方=4,用a.b表示log以25为底12的次方

人气：461 ℃　时间：2020-03-28 21:02:36

解答

已知,log5(3) = a ,log5(4) = b ,
可得：log25(12) = log5²(3×4) = (1/2)log5(3×4) = (1/2)[log5(3)+log5(4)] = (1/2)(a+b) .