(log8 27)÷(log4 9),一定要详细,1是怎么来的?
问题描述:
(log8 27)÷(log4 9),一定要详细,1是怎么来的?
答
(log8 27)÷(log4 9) 用换底公式,都换成以2为底的对数
=[(log2 27)/(log2 8)]÷[(log2 9)/(log2 4)]
=[(3log2 3)/(3log2 2)]÷[(2log2 3)/(2log2 2)]
=(log2 3)÷(log2 3)
=1请问只有换底公式,才能解决吗?