X P 60 0.1 70 0.2 80 0.7 EX?60?0.1?70?0.2?80?0.7?76 DX?162?0.1?62?0.2?42?0.7?44 （ii）购进17枝时，当天的利润为
y?(14?5?3?5)?0.1?(15?5?2?5)?0.2?(16?5?1?5)?0.16?17?5?0.54?76.4
76.4?76 得：应购进17枝 19、【解析】（1）在Rt?DAC中，AD?AC 得：?ADC?45?
同理：?A1DC1?45???CDC1?90?[来源:学科网]
得：DC1?DC,DC1?BD?DC1?面BCD?DC1?BC （2）DC1?BC,CC1?BC?BC?面ACC1A1?BC?AC
取A1B1的中点O，过点O作OH?BD于点H，连接C1O,C1H
? A1C1?B1C1C1O?CH?ABA1B1C1?面A1BD?C1O?面A1BD ，面1BD 得：点H与点D重合
OH?BD?1 且?C1DO是二面角A1?BD?C1的平面角
2a2 设AC?a，则C1O?，C1D??2a?2C1O??C1DO?30
? 既二面角A1?BD?C1的大小为30
20、【解析】（1）由对称性知：?BFD是等腰直角?，斜边BD?2p 点A到准线l的距离d?FA?FB? S?ABD?42?22p
12?BD?d?42?p?2
2 圆F的方程为x?(y?1)?8
x02 （2）由对称性设A(x0,2p)(x0?0)，则F(0,p2)
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点A,B关于点F对称得：B(?x0,p?3px022pp)?p?x022p??p2?x0?3p
22 得：A(3p,3p2)，直线m:y?22x?p?x?23p3333?3y?3p2?0
x?2py?y?2x22p?y??xp??x?p?切点P(3p3,p6)
直线n:y?p6?33(x?3p3)?x?3y?36p?0
坐标原点到m,n距离的比值为3p2:3p612?3。
x?121、【解析】（1）f(x)?f?(1)e?f(0)x?2x?1x?f?(x)?f?(1)e?f(0)?x
令x?1得：f(0)?1
x?1 f(x)?f?(1)e?x?122?1x?f(0)?f?(1)e?1?f?(1)?e
得：f(x)?e?x?
x122xx?g(x)?f?(x)?e?1?x
g?(x)?ex?1?0?y?g(x)在x?R上单调递增 f?(x)?0?f?(0)?x?0,f?(x)?0?f?(0)?x?0 得：f(x)的解析式为f(x)?e?x?x12x
2 且单调递增区间为(0,??)，单调递减区间为(??,0) （2）f(x)?12x?ax?b?h(x)?e?(a?1)x?b?0得h?(x)?e?(a?1)
2xx ①当a?1?0时，h?(x)?0?y?h(x)在x?R上单调递增 x???时，h(x)???与h(x)?0矛盾
②当a?1?0时，h?(x)?0?x?ln(a?1),h?(x)?0?x?ln(a?1) 得：当x?ln(a?1)时，h(x)min?(a?1)?(a?1)ln(a?1)?b?0 (a?1)b?(a?1)?(a?1)ln(a?1)(a?1?0)
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22
令F(x)?x2?x2lnx(x?0)；则F?(x)?x(1?2lnx) F?(x)?0?0?x? 当x? 当a?e,F?(x)?0?x?e e时，F(x)max?e?1,b?e2
e2e时，(a?1)b的最大值为
22、【解析】（1）CF//AB，DF//BC?CF//BD//AD?CD?BF CF//AB?AF?BC?BC?CD （2）BC//GF?BG?FC?BD
BC//GF??GDE??BGD??DBC??BDC??BCD??GBD
?5?4?11?23、【解析】（1）点A,B,C,D的极坐标为(2,),(2,),(2,),(2,)
3636 点A,B,C,D的直角坐标为(1,3),(?3,1),(?1,?3),(3,?1) ?x0?2cos?(?为参数) （2）设P(x0,y0)；则??y0?3sin? t?PA?PB?PC ?56?20s2i?n?222?PD?4x?4y?40
222 ,76][5624、【解析】（1）当a??3时，f(x)?3?x?3?x?2?3
x?22?x?3x?3??? ??或??或??
3?x?2?x?33?x?x?2?3x?3?x?2?3??? ?x?1或x?4
（2）原命题?f(x)?x?4在[1,2]上恒成立
?x?a?2?x?4?x在[1,2]上恒成立
??2?x?a?2?x在[1,2]上恒成立 ??3?a?0
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