[参考答案]
一、选择题(理)CBACD DCBCD AB (文)CBACD DCBCD AB 二、填空题
3 (13)14π (14)5 (15)4x?y?8?0 (16)(2,??)
2三、解答题
17.解:argz??4??2?tg(argz)?tg(???) (2分) 42 即sin?1?tg?2 即11?tg?1?cos???2 1?tg???2tg21?tg2 即tg2??2tg??1?0 (6分)
22 ?tg?2??1?2 ????分)
2?3?24?tg?2??1?2 (8 cos(???24)(cos??sin?)?1?2sin2??22 cos??2(1?tg?)2
2tg??2(1?2
2)?2[1?2(?1?2)1?tg2?21?(?1?2)2]?22? 即
cos(??4)?2 (12分) 1?2sin2?218.(理)解:(I)当M在A1C1中点时,BC1//平面MB1A
∵M为A1C1中点,延长AM、CC1,使AM与CC1延 长线交于N,则NC1=C1C=a
连结NB1并延长与CB延长线交于G, 则BG=CB,NB1=B1G (2分) 在△CGN中,BC1为中位线,BC1//GN
NA1MC1B1ACBG
又GN?平面MAB1,∴BC1//平面MAB1 (4分) (II)∵△AGC中, BC=BA=BG ∴∠GAC=90° 即AC⊥AG 又AG⊥AA1 AA1?AC? ?AG?平面A1ACC1A
AG?AM (6分)
∴∠MAC为平面MB1A与平面ABC所成二面角的平面角
?tg?MAC? a?21a2 ∴所求二面角为argtg2. (8分) (Ⅲ)设动点M到平面A1ABB1的距离为hM. VB?AB1M?VM?AB1B?1111333 S?ABB1?hM??a2hM?a2?a?a332621212 即B—AB1M体积最大值为3a3.此时M点与C1重合. (12分) 18.(文)(Ⅰ)同(理)解答,见上
(Ⅱ)同理科解答:设所求二面角为θ,则tg??2 (Ⅲ)VB?AMB?VM?ABB?1119.(理)解:(I)首先ax ax?bx?1112333
?a?a?a32224b?由a?1,得x?0 bxx?bx?0,即a?b即(a)x?11?ax?()x?1. (3分)
a 得(ax)2?ax?1?0解得ax?1?5(舍去)或ax?1?5
22 ?x?loga1?5 ?M?(log1?5,??) (6分)
a22(II)令
f(x)?ax?bx,先证f(x)在x?(0,??)时为单调递增函数
?0?x1?x2???,f(x1)?f(x2)?ax1?bx1?ax2?bx2?(ax1?ax2)?(bx2?bx1) ?a?1?b?0,x1?x2,?ax1?ax2,ax1?ax2?0,bx2?bx1,?bx2?bx1?0
?f(x1)?f(x2).得证 (8分)
欲使解集为(1,+∞),只须f(1)=1即可,即a-b=1,∴a=b+1 (12分) 19.(文)解:f?1(x)?loga(1?ax).由f?1(1)?loga(1?a)可知0<a<1 (4分)
?1 ∴不等式loga(1?ax)?f(1)即为loga(1?ax)?loga(1?a)(a?0)(8分)
?1?ax?0?ax?1 ???1?a?0???0?a?1?0?x?1
??1?ax?1?a??ax?a ∴原不等式的解集为{x|0<x<1} (12分 )
20.解:(I)由题意得3?x?k?1,将t?0,x?1代入得k?2 (2分)
t ?x?3?2
t?1 从而生产成本为32(3?2)?3万元,年收入为
t?1 xg(x)?x[3(32?32x)?t2x] (4分) ?y?xg(x)?[32(3?2t?1)?3]?x?[32(32?3x)?t2x]?[32(3?2t?1)?3] ?t2??98t?352(t?1)(t?0)
∴年利润为y??t2?98t?352(t?1)(t?0) (8分)
(II)y2??t?98t?352(t?1)?50?(t?1?32(万元)2t?1)?50?216?42 当且仅当t?1?32t?1即t?7时y (12分)
2max?42 ∴当促销费定为7万元时,利润最大.
21.解(I)以AB所在直线为x轴,AB中垂线为y轴,则A(-4,0),B(4,0) |PA|+|PB|=|PA|+|PM|=10 (2分) ∴2a=10 2c=8 ∴a=5,c=4
∴P点轨迹为椭圆x2225?y9?1 (4分)
(II)
mx?y?4m?0过椭圆右焦点B(4,0)
? ???x?y?4?y?m(x?4)???m(?m?0)
?x22?22??25?y9?1?x??25?y9?1 ?9(1m2y2?8my?16)?25y2?25?9?0 6分) (
整理得(9?25)y2?72y?81?0 (6分)
2mm?72?22??mm?1*(8分) 1 2m??90???|y1?y2|?(y1?y2)?4y1y2??4?81?25m2?9m29?9??25?2?25?m2?m? ∵m为直线的斜率,∴可令m=tgθ代入*得 |y?y|?12290tg2?1?tg2?90tg2?sec?90sin2?1?||??(?sin??0) 2222225tg??9tg?9?25tg?tg?9cos??25sin?|sin?|90sin??9?16sin2?9016sin??9sin??90216?9?9015 ?.244
? 当且仅当16sin??99 即sin2??sin?1615
即sin??3时,|y1?y2|max?.44 ??S?AEF?max?22.证:(I)令x 令
115?8??15. (12分) 24?y?0,则2f(0)?f(0),?f(0)?0
2xx?xy??x,则f(x)?f(?x)?f(0)?0,?f(?x)??f(x) 为奇函数 (4分)
nn (II)f(x)?f(1)??1, f(x)?f()?f(n)?f(xn)?f(xn)?2f(xn) n?11221?xn?xn1?xn ?f(xn?1)?2.即{f(x)}是以-1为首项,2为公比的等比数列.
nf(xn) ?f(xn)??2n?1 (4分) (III)(理)
111111??????(1??2???n?1) f(x1)f(x2)f(xn)222
1
2n??(2?1)??2?1??2??12n?12n?11?21? 而?2n?5??(2?1)??2?1??2.?1?1???1??2n?5(6分)
n?2n?2n?2f(x1)f(x2)f(xn)n?2
(III)(文)
111111??????(1??2???n?1) f(x1)f(x2)f(xn)222
1
2n??(2?1)??2?1??2.??12n?12n?11?21?