已知f(x)= ,则f(－9)等于（ ）

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='16566' and id < 1441255 and id<>'1441255' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='16566' and id > 1441255 and id<>'1441255' order by id asc limit 5