Question

若函數(shù)y＝f(x)的圖象與函數(shù)的圖象關(guān)于直線x-y=0對(duì)稱，則f(x)=
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Answer 1

-()

由題意判斷兩個(gè)函數(shù)互為反函數(shù)，然后求出函數(shù)y=x²（x≤0）的反函數(shù)即可．
解：函數(shù)y=f（x）的圖象與函數(shù)y=x²（x≤0）的圖象關(guān)于直線x-y=0對(duì)稱，
說明兩個(gè)函數(shù)互為反函數(shù)，函數(shù)y=x²（x≤0）的反函數(shù)是f^-1（x）=- (x≥0)
所以f（x）=- (x≥0)
故答案為：- (x≥0)