定义在R上的函数f（x）满足f（4）=1，f"（x）为f（x）的导函数，已知函数y=f"（x）的图象如图所示，若两正数a，b满足f（2a+b）＜1，则的取值范围是

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='14233' and id < 1170626 and id<>'1170626' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='14233' and id > 1170626 and id<>'1170626' order by id asc limit 5