log36 (45)=log18(45)/log18(36) =(log18 5+log18 9)/(log18 18 +log18 2) =(a+b)/(2-a)
问题描述:
log36 (45)=log18(45)/log18(36) =(log18 5+log18 9)/(log18 18 +log18 2) =(a+b)/(2-a)
没理解
答
log36(45)=lg45/lg36=(lg45/lg18)/(lg36/lg18)=log18(45)/log18(36)log18(5×9)=log18(5)+log18(9)l0g18(36)=log18(18)+log18(2)a=log18(9) ,b=log18(5) ,log18(324/9)=log18(324)-log18(9)=2-log18(9)=2-a