已知在定义域上是减函数,且,则的取值范围是
已知,则
设,若,则
函数的定义域为___________________
已知集合U={1,2,3,4,5,6,7}, A={2,4,5,7},B={3,4,5},则=___ _
设偶函数f(x)的定义域为R,当x时f(x)是增函数,则f(-2),f(),f(-3)的大小关系是:( )
A.f()>f(-3)>f(-2) B.f()>f(-2)>f(-3)
C.f()<f(-3)<f(-2) D.f()<f(-2)<f(-3)