54.　什么是函數(shù)的單調(diào)性?

答　設函數(shù)f(x)的定義域為D,區(qū)間I⊂D.如果ᗄx1,x2∈I,且x1<x2時,恒有f(x1)<f(x2),則稱f(x)在區(qū)間I上是單調(diào)增加的.如果ᗄx1,x2∈I,且x1<x2時,恒有f(x1)>f(x2),則稱f(x)在區(qū)間I上是單調(diào)減少的.單調(diào)增加和單調(diào)減少的函數(shù)統(tǒng)稱為單 ......    （本文共 177 字 ）     [閱讀本文] >>