(3)F?x??a ??x?1??f?x??g?x??aloga?x?1??logax2?3x?3???3??,x??? (14分)
x2?3x?3?2??x?1?7?5?27?5,当且仅当x?7?1时等号成立, x?1x?1 ?2?x?3x?3?27?5????, (16分) ?0,73??x?1???5?x?11 ?3?当
27?5?4,?F?x?有可能取的整数有且只有1,2,3. 3x?1?1时,解得x?2?2,x?2?2(舍去);
x2?3x?3x?15?2时,解得x?,x?1(舍去)当2;
2x?3x?3当
x?14?5??3x?2,x?时,解得(舍去).故集合M?2,,2?2??(18分)
3x2?3x?3?2?(文科)(1)由已知得 f?x??loga?x?1?; (4分) (2)?a?1,?f?x?在??1,???上为单调递增函数, (6分)
?在区间?m,n??m??1?,
g?m??loga?m?1??loga 即m?1?2pp,g?n??loga?n?1??loga; mnppp,n?1?,n?m??1. ?m,n是方程x?1? mnx即方程x?x?p?0,x???1,0???0,???的两个相异的解, (8分)
????1?4p?0?12这等价于???1????1??p?0, (10分) 解得??p?0为所求. (12分)
4?1????1?22另解:可转化为函数y?x?x,x???1,0???0,???图像与函数y?p的图像有两个交点
问题,数形结合求得:?(3)F?x??af?x??g?x?1?p?0. 4loga?x?1??logax2?3x?3?a????x?1?x2?3x?3,?x??1? (14分)
??x?1??7?5?27?5,当且仅当x?7?1时等号成立, x?1 ?x?1?2x?3x?3?27?5????, (16分) ?0,73??x?1???5?x?11?F?x?max?F7?1???27?5, 3?w?F?x?恒成立,?w?F?x?max,
所以w?27?53为所求. 18分) (