设函数f(x)=log1/2(1-1/2x) 1.证明(x)=log1/2 (1-1/2 x)在(-∞,1/2)上是增函数2.解不等式:f(x)>1

问题描述:

设函数f(x)=log1/2(1-1/2x) 1.证明(x)=log1/2 (1-1/2 x)在(-∞,1/2)上是增函数
2.解不等式:f(x)>1

(1)设x1<x2<1/2∴f(x1)-f(x2)=㏒1/2 [ (2-x1)/(2-x2)]∵x1<x2<1/2 ∴﹣x1>﹣x2 ∴2-x1>2-x2>0 ∴ (2-x1)/(2-x2)>1∴f(x1)-f(x2)=㏒1/2 [ (2-x1)/(2-x2)]<㏒1/2 1=0 ∴f(x1)<f(x2)∴f(x)=log1...