Question

设命题甲:的解集是实数集R;命题乙:,则命题甲是命题乙成立的   (     )                                                                                                                                   

A . 充分非必要条件             B.必要非充分条件        

C. 充要条件                          D. 既非充分又非必要条件

Answer 1

B.

解析:

的解集是实数集

             ①a=0, 则1>0恒成立

②a≠0,则,故0<a<1

由①②得