嘉定区2009学年度高三年级第一次质量调研数学试卷参考答案与评分标准
一.填空题 1.2?i;2.
x?1(x?1);3.{x1?x?3};4.1:3;5.?2425;6.29;
7.x1?2,x2?log2?331?5;8.??; ,?;9.{aa??2或a?2};10.
?1022??
二.选择题
15.B; 16.D; 17.A; 18.(理)D;(文)C.
三.解答题
2?a?①?2?4i?t19.(理)(1)由题意可得,a?bi? ,?(3?3ati,所以?t4?b?3at?②?t?分)
22由①得,t?,代入②得b?3a??2a,所以2a?b?6.????(6分)
aa(2)由|z?2|?5得|(a?2)?bi|?5,即(a?2)2?b2?5,??(8分) 由(1)得b?6?2a,所以(a?2)2?(6?2a)2?25, 化简得5a2?28a?15?0,????(10分) 所以a的取值范围是??3?,5?.????(12分) ?5?
19.(文)(1)z1?z2?(1?i)(t?i)?(t?1)?(t?1)i,??(3分) 由已知,z1?z2是实数,所以t?1?0,即t?1.????(6分)
(2)由|z1?z2|?22,得|(1?t)?2i|?22,即(1?t)?4?22,??(8分) 即(t?1)?4?8,解得?3?t?1.??(11分) 所以t的取值范围是[?3,1].????(12分)
20.(1)因为三棱柱的体积V?33,而S底?所以S侧?3?2?3?18.??(6分) (2)取AC中点E,连结DE、C1E, 则ED∥AB,所以,?C1DE(或其补角) 就是异面直线AB与C1D所成的角.??(8分) 在△C1DE中,C1D?C1E?DE?1,????(9分)
2234?4?3,所以A1A?3??(3分)
A1
B1 C1
A E C
B
D
10,
所以cos?C1DE?1210?1020.????(12分)
1020所以,异面直线AB与C1D所成角的大小为arccos(或arcsin
21.(1)由题意得,S分) 解得y?3x△ADE.????(14分)
39020,或arctan39) 121214?S△ABC,即?x?y?sinA??AB?AC?sinA,?(4
A ,??(5分)
3x所以f(x)?,f(x)的定义域为[1,2].????(7分)
D (2)在△ADE中,由余弦定理得,
B 222DE?AD?AE?2?AD?AE?cosA
DE2E
?x?y?2xycos609x2220?x?y?xy
22C
?x?2?3,x?[1,2],????(10分)
2令x2?t,则t?[1,4],于是DE当且仅当t?3,即x??t?9t?3?6?3?3,??(12分)
3时,DE2取最小值3.??(13分)
3(m)时),DE最短,
所以,当D、E离点A的距离均为3m时(或AD?AE?即所用石料最省.????(14分)
2??x?x?1,x?122.(理)(1)当a?1时,f(x)?x|x?1|?1?? ,??(1分)
2???x?x?1,x?122所以,当x?1时,由f(x)?x得x?x?1?x,x?2x?1?0,解得x?1?2,
因为x?1,所以x?1?2.????(2分)
2.????(4分)
22当x?1时,由f(x)?x得?x?x?1?x,x??1,无实数解.??(3分)
所以,满足f(x)?x的x值为1?2??x?ax?a,x?a(2)f(x)?? ,??(5分)
2???x?ax?a,x?a
?a2?a???,因为a?0,所以,当x?a时,f(x)??x????的单调递增区间是[a,??); ?a??2???4??a2?a?a??,单调递增区间是(??,].?(8分) 当x?a时,f(x)???x?????a?4?22????(注:两个区间写出一个得2分,写出两个得3分,区间不分开闭)
22所以,f(x)的单调递增区间是(??,
(3)由x|x?a|?a?0, 当x?a时,x2?ax?a?0,
a2]和[a,??).????(9分)
?a?因为f(a)??a?0,所以x??a,??2a?4a??.??(11分)
?2??a2?a??2??0, ?a当x?a时,?x?ax?a?0,即??x?????4?2????2当
a24a2?a?0,即0?a?4时,x?(??,a);??(13分)
2a?4a????2??a?当?a?0,即a?4时,x????,?4??a????a?4a22?,a?.?(14??分)
?a?综上可得,当0?a?4时,x????,???a?当a?4时,x????,??2a?4a????2?2a?4a??,
?2??a????a?4a22,a?2a?4a??.??(16分)
?2?2??x?x?1,x?122.(文)(1)f(x)?x|x?1|?1?? ,??(1分)
2???x?x?1,x?122所以,当x?1时,由f(x)?x得x?x?1?x,x?2x?1?0,解得x?1?2,
因为x?1,所以x?1?2.????(2分)
22当x?1时,由f(x)?x得?x?x?1?x,x??1,无实数解.??(3分) 所以,满足f(x)?x的x值为1?2.????(4分)
2??x?x?1,x?1(2)由f(x)?? ,
2???x?x?1,x?1当x?1时,f(x)的单调递增区间为[1,??);??(6分)
当x?1时,f(x)的单调递增区间为(??,所以,f(x)的单调递增区间是(??,1212].??(8分)
]和[1,??).????(9分)
(3)当x?1时,由x2?x?1?0得1?x?1?25,????(12分)
当x?1时,由?x2?x?1?0得x2?x?1?0,恒成立.??(15分) 所以,不等式f(x)?0的解集为???, 23.(理)(1)当x1?x2?1时,
y1?y2?f(x1)?f(x2)?log2x12???1?5??.??(16分) 2??1?x1?log2x221?x2?2x12x2??log2???
?1?x11?x2????log2x1x22x2x1?log22?1,所以y1?y2为定值1.????(4分)
(2)由(1)得,f?所以,Tn?f?又 Tn?f??k??n?k?,??(6分) ??f???1(k?1,2,?,n?1)
?n??n??1??2??n?2??n?1???f?????f???f??, ?n??n??n??n??n?1??n?2??2??1???f?????f???f??, ?n??n??n??n?n?1于是2Tn?(n?1)?1,所以Tn?(n?N*,n?2).??(10分)
2(3)由已知,an?2n,n?N*.??(11分)
?1??1??1?????1????1?1?由???????aaa1??2?n???sin?2n?1,得
?1??1??1???sin?, ??1????1?2n?1??1??????a1??a2??an???令f(n)??1??1??1??,则由题意可得f(n)?0, ??1????1?2n?1??1??????a1??a2??an????1??1??1??1??1???1????1?2n?3?1?????a1?a2?an?an?1????????1??1??1????1????1?2n?1?1??????a1??a2??an????????12n?3?1??an?1?2n?1????于是
f(n?1)f(n)??