已知5^a=4,log5 3=b,求证log125 12=1/3(a+b)附求解题过程,多谢!_数学解答

已知5^a=4,log5 3=b,求证log125 12=1/3(a+b)
附求解题过程,多谢!

人气：462 ℃　时间：2020-05-09 13:51:44

解答

5^a=4,log5 3=b
==>log5 4=a
log125 12=log(5^3) 12
=(1/3)log5 12 =(1/3)log5 3*4
=1/3)(log5 3 +log5 4)
=(1/3)(a+b)