Question

函數(shù)的值域為           ．

Answer 1

[―2, ―1]

試題分析：因為，而對數(shù)的底數(shù)，故，函數(shù)的值域為[―2, ―1]。
點評：小綜合題，本題綜合考查指數(shù)函數(shù)、對數(shù)函數(shù)的性質(zhì)及函數(shù)的值域，涉及指數(shù)函數(shù)、對數(shù)函數(shù)問題，首先要關(guān)注底數(shù)的取值情況。