函數(shù)的圖象與其反函數(shù)的圖象有公共點(diǎn)，則實(shí)數(shù)a的取值范圍是：________．

函數(shù)y＝的圖象與其反函數(shù)的圖象有公共點(diǎn)，則實(shí)數(shù)a的取值范圍是________．

函數(shù)f(x)=(x≥a)的圖象與其反函數(shù)有公共點(diǎn)，則實(shí)數(shù)a的取值范圍是________。