Question

已知函數(shù)f(x)＝e^|x－a|(a為常數(shù))．若f(x)在區(qū)間[1，＋∞)上是增函數(shù)，則a的取值范圍是________．

Answer 1

(－∞，1]

由f(x)＝知函數(shù)f(x)在[a，＋∞)上是增函數(shù)．依題意[1，＋∞)⊆[a，＋∞)，∴a≤1.