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高三教学质量检测考试
数学试题参考答案及评分标准
说明:
一、本解答只给出一种解法供参考,如考生的解法与本解答不同,可根据试题的主要考
查内容参照评分标准酌情赋分.
二、当考生的解答在某一步出现错误时,如果后继部分的解答未改变该题的内容与难度,
可视影响的程度决定后继部分的给分,但不得超过该部分正确答案应得分数的一半;
如果后继部分的解答有较严重的错误或又出现错误,就不再给分.
三、解答右端所注分数,表示考生正确做到这一步应得的累加分数.
四、只给整数分数,选择题和填空题不给中间分.
一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一
项是符合题目要求的。
题号 1 2 3 4 5 6 7 8
答案 A A D B C C C D
二、选择题:本题共3小题,每小题6分,共18分。在每小题给出的四个选项中,有多项
符合题目要求。全部选对的得6分,部分选对的得部分分,有选错的得0分。
题号 9 10 11
答案 AD BC ACD
三、填空题:本题共3小题,每小题5分,共15分。
1
12.24 3;13.12;14. .
3
四、解答题:共77分.解答应写出文字说明、证明过程或演算步骤。
15.【解析】
(1)因为 底面ABCD为矩形,所以CD AD,
又因为PACD,PAAD A,
所以CD平面PAD,····································································· 3分
因为CD平面ABCD,
所以平面PAD平面ABCD;·····························································5分
数学试题答案 第1页(共6页)
{#{QQABDQaswgg4kETACB4KEQVcCQoQkIGiLUoExQAbKAxKwIFABIA=}#}(2)取AD中点为O,连接OP,因为△PAD为等边三角形,所以OP AD,
因为平面PAD平面ABCD,所以OP平面ABCD;
如图,分别以OA,OP为x,z轴建立空间直角坐标系,······························7分
1 1 3
则B( ,2,0),C( ,2,0),P(0,0, ) ,
2 2 2
1 3
所以BC (1,0,0),BP( ,2, ) ;
2 2
设平面PBC 的法向量为n(x,y,z),
x0
nBC 0
则
,即
1 3
,
nBC 0 x2y z0
2 2
取z4,则n(0,3,4);······························································10分
又平面PAD的法向量为m(0,1,0);·················································11分
mn 3 57
设平面PAD与平面PBC 夹角为,则cos ,
|m||n| 19 19
57
所以平面PAD与平面PBC 夹角的余弦值为 .·································13分
19
16.【解析】
(1)函数 f(x)的定义域为(,),
x 1
f(x) axx(a ),································································1分
ex ex
1
若a0,a 0恒成立,
ex
所以 f(x)在(,0)上单调递增,在(0,)上单调递减;························3分
若a0,令 f(x)0,x0或xlna;
当0a1时, f(x)在(,0)上单调递增,
在(0,lna)上单调递减,在(lna,)上单调递增;····························· 4分
当a1时, f(x)≥0恒成立, f(x)在(,)上单调递增;···················5分
当a1时, f(x)在(,lna)上单调递增,
在(lna,0)上单调递减,在(0,)上单调递增;···································6分
(2)若0a1,当x(1,), f(x)0恒成立,
当x(,1)时, f(x)单调递增,
不可能有两个零点;··········································································9分
数学试题答案 第2页(共6页)
{#{QQABDQaswgg4kETACB4KEQVcCQoQkIGiLUoExQAbKAxKwIFABIA=}#}若a1,因为 f(x)在(,lna)上单调递增,
在(lna,0)上单调递减,在(0,)上单调递增;
所以 f(x)的极小值 f(0)1a0,
故不可能有两个零点;······································································12分
若a0, f(x)在(,0)上单调递增,在(0,)上单调递减;
因为 f(x)有两个零点,则必有 f(0)1a0,即1a0;
此时,当x时, f(x);当x时, f(x);
故 f(x)有两个零点,符合题意,
综上 1a0.············································································15分
17.【解析】
(1)第四场结束恰好分出胜负对应的事件为
A :{甲赢第1、3、4局,乙赢第2局},
1
A :{甲赢第2、3、4 局,乙赢第1局},
2
A :{乙赢第1、3、4局,甲赢第2局},
3
A :{乙赢第2、3、4 局,甲赢第1局},
2
15
对应概率:P(A A A A )2p3(1 p)2(1 p)3p ;···················6分
1 2 3 4 64
(2)设事件A:{甲最终获胜},事件B:{甲乙在前两局结束后得分相同}.
记使用方案一、二时甲胜出的概率分别为P(A),P(A).
1 2
对于方案一,根据条件概率公式:
P(A)P(AB)P(AB) p2 P(A|B)P(B) p2 2p(1 p)P(A|B),
因为每场比赛的结果相互独立,所以在前两局甲、乙各胜出一局达到同分的条件下,
甲从第三局开始出现优先超过乙两分的概率恰为P(A),即P(A|B)P(A),
故P(A) p2 2p(1 p)P(A),
p2
从而P(A) .··································································9分
1 2p2 2p1
对于方案二,甲最终获胜对应的事件只可能是甲乙相互获胜且最后甲连胜两局,即每
局胜者按照“甲乙甲乙…甲乙甲甲”或“乙甲乙甲…乙甲甲”的规律.
从而甲获胜的概率
数学试题答案 第3页(共6页)
{#{QQABDQaswgg4kETACB4KEQVcCQoQkIGiLUoExQAbKAxKwIFABIA=}#} 2p2 p3
P(A) p2 pn(1 p)n ppn(1 p)n ,·····························12分
2 p2 p1
n0 n1
P(A) 1 1
显然P(A)0,令 1 1,有(p )(p1)2 0,即 p .
2 P(A) 2 2
2
故我们有P(A)P(A),应选择方案二.··············································15分
1 2
18.【解析】
p 5
(1)由题意可知 2 3 3 ,所以p1.
2 2
所以抛物线E的标准方程为:x2 2y.··············································· 4分
(2)设P x ,y ,B x ,y ,D x ,y
0 0 1 1 2 2
x x 2 y y
(i)由题意,PB中点 A在抛物线E上,即
0 1
2 0 1 ,
2 2
x2
又x2 2y ,将 y 1 代入,
1 1 1 2
得:x2 2x x 4y x2 0,··························································6分
1 0 1 0 0
同理:x2 2x x 4y x2 0,
2 0 2 0 0
x x 2x
有 1 2 0 ,
x x 4y x2
1 2 0 0
x x
此时M 点横坐标为 1 2 x ,························································8分
2 0
所以直线
PM x
轴;········································································9分
y y x2x2 x x 22x x 3x2 4y
(ⅱ)因为 1 2 1 2 1 2 1 2 0 0 ,
2 4 4 2
3x2 4y
所以点M x , 0 0 ,·····························································11分
0 2
1
此时S PM x x ,
2 1 2
3x2 4y 3
PM 0 0 y x2 2y ,
2 0 2 0 0
x x x x 24x x 8 x22y ,
1 2 1 2 1 2 0 0
数学试题答案 第4页(共6页)
{#{QQABDQaswgg4kETACB4KEQVcCQoQkIGiLUoExQAbKAxKwIFABIA=}#}所以S 3 2 x2 2y 3 ,··························································14分
2 0 0
又因为点P在圆Q上,有 y 2 2 x2 3,即x2 y2 4y 1,
0 0 0 0 0
代入上式可得:S 3 2 y26y 1 3 3 2 y 3 28 3 ,
2 0 0 2 0
由2 3 y 2 3,
0
所以 y 3时,S取到最大值 3 2 83 48.
0
2
所以S的最大值为48. ····································································17分
19.【解析】
(1)对任意元素xA△C,因为x恰属于集合A,C之一,不妨设xA且xC.
若xB,则xB△C;若xB,则xA△B.
故x(A△B)(B△C).·································································2分
从而AC (AB) BC .
因此 A△C A△B B△C ,结论成立.···········································4分
(2)首先当l n时,显然该集合元素个数为0.·········································· 5分
下面考虑l n的情形:对任意一个S 的l元子集T ,我们有:
n
X△M T T {x|xX,xM或xM,xX} X {x|xT,xM或xM,xT}
X T△M ,即每个T 恰唯一对应一个X 属于该集合.·····················8分
故该集合的元素个数为Cl.
n
Cl ,ln
综上所述,该集合元素个数为 n .············································· 9分
0,l n
(3)对每个i 1im ,考虑集合Y {Y |Y S ,Y△X k}.
i n i
若集合YY Y ,则Y△X ,Y△X k ,故由(1)知:
i j i j
X △X X △Y Y△X kk 2k 2k1,矛盾!
i j i j
故集合Y,Y ,...,Y 两两不交.····························································13分
1 2 m
数学试题答案 第5页(共6页)
{#{QQABDQaswgg4kETACB4KEQVcCQoQkIGiLUoExQAbKAxKwIFABIA=}#}k
结合(2)知:Y Cj Ck1Ck Ck .
i n n n n1
j0
m
因此mCk Y {X |X S } 2n ,
n1 i n
i1
结论成立.·····················································································17分
数学试题答案 第6页(共6页)
{#{QQABDQaswgg4kETACB4KEQVcCQoQkIGiLUoExQAbKAxKwIFABIA=}#}