(0,1]
分析:由已知中函數(shù)f(x)的圖象與g(x)=(
)
x的圖象關(guān)于直線y=x對(duì)稱,可得函數(shù)f(x)與g(x)=(
)
x互為反函數(shù),由此易得到函數(shù)f(x)的解析式,結(jié)合復(fù)合函數(shù)同增異減的原則,即可得到f(2x-x
2)的單調(diào)遞減區(qū)間.
解答:因?yàn)閒(x)與g(x)互為反函數(shù),所以f(x)=
x
則f(2x-x
2)=
(2x-x
2),
令μ(x)=2x-x
2>0,解得0<x<2.
μ(x)=2x-x
2在(0,1)上單調(diào)遞增,
則f[μ(x)]在(0,1)上單調(diào)遞減;
μ(x)=2x-x
2在(1,2)上單調(diào)遞減,
則f[μ(x)]在[1,2)上單調(diào)遞增.
所以f(2x-x
2)的單調(diào)遞減區(qū)間為(0,1]
故答案為:(0,1]
點(diǎn)評(píng):本題考查的知識(shí)點(diǎn)是反函數(shù),根據(jù)互為反函數(shù)的圖象關(guān)于直線y=x對(duì)稱,及同底數(shù)的指數(shù)函數(shù)和對(duì)數(shù)互為反函數(shù)求出函數(shù)f(x)的解析式,是解答本題的關(guān)鍵.