A解析分析:先設(shè)出函數(shù)解析式,再把點(diǎn)的坐標(biāo)代入,求出底數(shù),即可得解解答:設(shè)對數(shù)函數(shù)解析式為y=logax(a>0,a≠1,x>0)∵函數(shù)的圖象過點(diǎn)M(16,4)∴l(xiāng)oga16=4∴a4=16又∵a>0∴a=2∴此對數(shù)函數(shù)的解析式為y=log2x故選A點(diǎn)評:本題考查對數(shù)函數(shù)的求解以及對數(shù)式與指數(shù)式的互化.屬簡單題