已知函數(shù)f(x)=log3(x-1)+9,若函數(shù)y=g(x)的圖象與y=f(x)的圖象關(guān)于直線y=x對(duì)稱,則g(10)的值為( )
A.1
B.4
C.10
D.11
【答案】分析:由已知,得出y=g(x)與y=f(x)互為反函數(shù),利用原函數(shù)與反函數(shù)的關(guān)系求解.
解答:解:若函數(shù)y=g(x)的圖象與y=f(x)的圖象關(guān)于直線y=x對(duì)稱,即是y=g(x)與y=f(x)互為反函數(shù).
設(shè)g(10)=a,則應(yīng)有f(a)=10,即log3(a-1)+9=10,
∴l(xiāng)og3(a-1)=1,
∴a-1=3,a=4.
故選B
點(diǎn)評(píng):本題考查函數(shù)圖象與函數(shù)值求解.利用圖象的關(guān)系進(jìn)行轉(zhuǎn)化是本題的關(guān)鍵.