(2)det(A)?2?111?3,
1?3?.………………10分 2??3???),B( 9,),线段AB的垂直平分线l与极轴交于33?1??1?1??3???3A?1??312??1?????3??3?321B.在极坐标系中,已知A( 1,
点C,求l的极坐标方程及?ABC的面积. 解:由题意,线段AB的中点坐标为(5,),
3设点P(?,?)为直线l上任意一点, 在直角三角形OMP中,?cos(??)?5,
3所以,l的极坐标方程为?cos(??)?5,………………5分
3令??0,得??10,即C(10,0).(8分)
???1?所以,?ABC的面积为:?(9?1)?10?sin?203.………………10分
2322.(本小题満分10分)
?m(x?1)?2,x?0,?x已知函数f(x)??是奇函数.
1?2(x?)?n,x?0x?(1)求实数m,n的值:
(2)若对任意实数x,都有f(e)??f(e)?0成立.求实数的取值范围.
2xx
23.(本小题满分10分)
已知?1?x?2n?1?a0?a1x?a2x?…?a2n?1x22n?1,记Tn?n?N.
*??2k?1?ak?0nn?k.
(1)求T2的值;
(2)化简Tn的表达式,并证明:对任意的n?N*,Tn都能被4n?2整除.
210解:(1)T2?a2?3a1?5a0?C5?3C5?5C5?30.………………3分
(2) ∵?n?1?k?Cnn?1?k2n?12n?1?!2n?1???2n?!??n?k??n?1?k?????2n?1?C2n
?n?1?k?!?n?k?!?n?k?!?n?k?!???2k?1?Ck?0n?1?k2n?1nn?k2n?1n?1?k???2k?1?C2n?1 k?0n∴Tn?n??2k?1?ak?0n?k????2?n?1?k???2n?1???Ck?0?2??n?1?k?Ck?0nn?1?k2n?1n?1?k??2n?1??C2n?1
k?0n?2?2n?1??Ck?0nn?k2n12n12n?1?1?kn??2n?1??Cn?22n?1??2?C?2n?1??2??2n?1?Cn??????2n?12n2n22k?0n??
………………7分
n?1nn∴Tn??2n?1?Cn2n??2n?1?C2n?1?C2n?1?2?2n?1?C2n?1.
??∵C2n?1?N,
∴Tn能被4n?2整除.………………10分
n*