B
分析:利用函數(shù)y=a
x的反函數(shù)的圖象經(jīng)過(guò)點(diǎn)

,可知點(diǎn)(a,

)在函數(shù)y=a
x的圖象上,由此代入解析式即可求得.
解答:依題意,點(diǎn)

在函數(shù)y=a
x的反函數(shù)的圖象上,
則點(diǎn)(a,

)在函數(shù)y=a
x的圖象上
將x=a,y=

,代入y=a
x中,
得

=a
a
即,

=a
a,又a>0且a≠1
∴a=

故選B.
點(diǎn)評(píng):本題考查了互為反函數(shù)的函數(shù)圖象之間的關(guān)系,巧妙的利用互為反函數(shù)的函數(shù)圖象間的關(guān)系,將反函數(shù)圖象上的點(diǎn)轉(zhuǎn)化為原函數(shù)圖象上的點(diǎn),屬于基礎(chǔ)題.