若 2^6a=3^3b=6^2c,求证: 3ab-2ac=bc.
问题描述:
若 2^6a=3^3b=6^2c,求证: 3ab-2ac=bc.
答
设2^6a=3^3b=6^2c=k则6a=log(2,k)=1/log(k,2).3b=log(3,k)=1/log(k,3)2c=log(6,k)=1/log(k,6)=1/[log(k,2)+log(k,3)]=1/[1/6a+1/3b]即1/2c=1/6a+1/3b得3ab-2ac-bc=0解此题的关键在于设 ,然后进行指对互化,再进行对...