Question

若－1<x<0,则下列不等式中成立的是

A.5^－x<5^x<0.5^x                                                                                                    B.5^x<0.5^x<5^－x

C.5^x<5^－x<0.5^x 

D.0.5^x<5^－x<5^x

Answer 1

解析:由－1<x<0，得5^x<1,0.5^x>1,5^－x>1.

又5^－x=()^x,0.5^x=()^x,故5^－x>0.5^x.

比较0.5^x与5^－x大小可用特殊值法.

答案:B