x1?x21?a211?a22a111?a22)??()??ln???(ln??1) 又?(22a221?a2aa1?a2222由①式知,取x?2,则x?0且x?1,得ln2?2?1?0
a?1a?1a?1a2?12x?x2)?2?1?0 ??(1?ln?0 22a?1又x0是F(x)的极值点,?F?(x0)?0,即?(x0)?0
??(x1x2)??(x0)??(x1?x2) 2x1?x2………………………12分 2又?(x)在(0,??)上单调递增 ?x1x2 ?曲线C1的普通方程为:(x?2)2?(y?3)2?4(0?x?4,1?y?3) ?曲线C2的极坐标方程为?(222sin??cos?)?t 222?曲线C2的直角坐标方程为x?y?t?0………………………………5分 (2)?曲线C1的普通方程为:(x?2)2?(y?3)2?4(0?x?4,1?y?3) 为半圆弧,由曲线C2与C1有两个公共点,则当C2与C1相切时, |2?3?t|得?2?|t?1|?22 2?t??22?1或t=22?1(舍去) 当C2过点(4,3)时,4-3+t=0 ?当C1与C2有两个公共点时,1?22?t??1……………………………10分 23.解(1)若m=2时,|x?1|?|2x?2|?3 44当x??1时,原不等式可化为?x?1?2x?2?3得x??,所以??x??1 33当?1?x?1时,原不等式可化为1?x?2x?2?3得x?0,所以?1?x?0 当x?1时,原不等式可化为x?1?2x?2?3得x?2,所以x?? 34综上述:不等式的解集为{x|??x?0}…………………………………5分 3(2)当x?[0,1]时,由f(x)?|2x?3|得1?x?|2x?m|?3?2x 即|2x?m|?2?x 故x?2?2x?m?2?x得?x?2?m?2?3x 又由题意知:(?x?2)min?m?(2?3x)max 即?3?m?2…………………………………10分 11