东莞市2021-2022学年高三上学期期末考试
数学
一、单项选择题:本大题共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. 请把正确选项在答题卡中的相应位置涂黑.
1. 设集合,,则
A. B. C. D.
2. 的展开式中项的系数是
A. 9 B. 10 C. 11 D. 12
3. 已知函数,,则下列结论正确的是
A. 是偶函数 B. 是奇函数
C. 是奇函数 D. 是奇函数
4. 若,,则
A. B. 1 C. D.
5. 甲乙两人在数独APP上进行“对战赛”,每局两人同时解一道题,先解出题的人赢得一局,假设无平局,且每局甲乙两人赢的概率相同,先赢3局者获胜,则甲获胜且比赛恰进行了4局的概率是
A. B. C. D.
6. “中国天眼”(如图1)是世界最大单口径、最灵敏的射电望远镜,其形状可近似地看成一个球冠(球冠是球面被平面所截的一部分,如图2所示,截得的圆叫做球冠的底,垂直于截面的直径被截得的线段叫做球冠的高.若球面的半径是,球冠的高度是,则球冠的面积).已知天眼的球冠的底的半径约为250米,天眼的反射面总面积(球冠面积)约为25万平方米,则天眼的球冠高度约为
(参考数值)
图1 图2
A. 52米 B. 104米 C. 130米 D. 156米
7. 已知直线过抛物线:的焦点,且与该抛物线交于两点.若线段的长为16,的中点到轴距离为6,则(为坐标原点)的面积是
A. B. C. D.
8. 已知为坐标原点,点为函数图象上一动点,当点的横坐标分别为时,对应的点分别为,则下列选项正确的是
A. B. C. D.
二、多项选择题:本大题共4小题,每小题5分,共20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5分,有选错的得0分,部分选对的得2分. 请把正确选项在答题卡中的相应位置涂黑.
9. 已知复数,是的共轭复数,则下列结论正确的是
A. 若,则 B. 若,则
C. 若,则 D. 若,则
10. 已知函数,若且对任意都有,则下列结论正确的是
A. B.
C. 的图象向左平移个单位后,图象关于原点对称
D. 的图象向右平移个单位后,图象关于y轴对称
11. 气象意义上从春季进入夏季的标志为“当且仅当连续天每天日平均温度不低于”.现有甲、乙、丙三地连续天日平均温度的记录数据(数据均为正整数,单位)且满足以下条件:
甲地:个数据的中位数是,众数是;
乙地:个数据的中位数是,平均数是;
丙地:个数据有个是,平均数是,方差是;
根据以上数据,下列统计结论正确的是
A. 甲地进入了夏季 B. 乙地进入了夏季
C. 不能确定丙地进入了夏季 D. 恰有2地确定进入了夏季
12. 已知函数,则下列结论正确的是
A. B.
C. 关于的方程的所有根之和为
D. 关于的方程的所有根之积小于
三、填空题:本大题共4小题,每小题5分,共20分. 请把答案填在答题卡的相应位置上.
13. 已知为双曲线:的一个焦点,则点到双曲线的一条渐近线的距离为_______.
14. 已知一个圆锥的底面半径为,其侧面积为,则该圆锥的体积为___________.
15. 桌面上有一张边长为2的正三角形的卡纸,设三个顶点分别为,,,将卡纸绕顶点顺时针旋转,得到、的旋转点分别为、,则_________.
16. 龙曲线是由一条单位线段开始,按下面的规则画成的图形:将前一代的每一条折线段都作为这一代的等腰直角三角形的斜边,依次画出所有直角三角形的两段,使得所画的相邻两线段永远垂直(即所画的直角三角形在前一代曲线的左右两边交替出现). 例如第一代龙曲线(图3)是以为斜边画出等腰直角三角形的直角边,所得的折线图,图4、图5依次为第二代、第三代龙曲线(虚线即为前一代龙曲线). ,,为第一代龙曲线的顶点,设第代龙曲线的顶点数为,由图可知,,,则_____;数列的前项和________.
图3 图4 图5
四、解答题:本大题共6小题,第17题10分,18、19、20、21、22题各12分,共70分. 解答应写出文字说明、证明过程或演算步骤. 必须把解答过程写在答题卡相应题号指定的区域内,超出指定区域的答案无效.
17. (本小题满分10分)
的内角的对边分别为,已知.
(1)求;
(2)若,的面积为,求的周长.
18. (本小题满分12分)
设等差数列的前项和为,且,.
(1)求数列的通项公式;
(2)在任意相邻两项和之间插入个1,使它们和原数列的项构成一个新的数列,求数列的前200项的和.
19. (本小题满分12分)
如图6,在正四棱锥中,点,分别是,中点,点是上的一点.
(1)证明:;
(2)若四棱锥的所有棱长为,求直线与平面所成角的正弦值的最大值.
图6
20. (本小题满分12分)
已知某次比赛的乒乓球团体赛采用五场三胜制,第一场为双打,后面的四场为单打.团体赛在比赛之前抽签确定主客队. 主队三名选手的一单、二单、三单分别为选手、、,客队三名选手的一单、二单、三单分别为选手、、. 比赛规则如下:第一场为双打(对阵)、第二场为单打(对阵)、第三场为单打(对阵)、第四场为单打(对阵)、第五场为单打(对阵). 已知双打比赛中获胜的概率是,单打比赛中、、分别对阵、、时,、、获胜的概率如下表:
选手 选手
(1)求主、客队分出胜负时恰进行了3场比赛的概率;
(2)客队输掉双打比赛后,能否通过临时调整选手为三单、选手为二单使得客队团体赛获胜的概率增大?请说明理由.
21. (本小题满分12分)
已知点为椭圆的左顶点,点为右焦点,直线与轴的交点为,且,点为椭圆上异于点的任意一点,直线交于点.
(1)求椭圆的标准方程;
(2)证明:.
22. (本小题满分12分)
已知且,函数.
(1)若,求函数在处的切线方程;
(2)若函数有两个零点,求实数的取值范围.
高三数学 第2页(共4页)2021-2022学年度第一学期教学质量检查
高三数学 参考答案
一、单项选择题
题号 1 2 3 4 5 6 7 8
答案 A B C B D C B D
二、多项选择题(全部选对的得 5分,选对但不全的得 2分,有选错的得 0分)
题号 9 10 11 12
答案 ABC BD AC ACD
三、填空题(16题第一空 2分,第二空 3分)
1 1
13.4 14. 12 15. 4 2 3 16. 17; 3 2n 1 1
四、解答题
a b c
17. 解:(1)方法一:因为 a2 b cosC c cosB ,由正弦定理 ,sin A sin B sinC
得 a sin A sin B cosC sinC cosB,·································································· 2分
即asin A sin(B C),·····················································································3分
由B C A,得 asin A sin(B C) sin A,················································ 4分
因为 sin A 0,所以 a 1 .·················································································· 5分
a2 b2 c2 a2 c2 b2
方法二:因为 a2 b cosC c cosB ,由余弦定理得 a2 b c ,·······2分
2ab 2ac
化简得 2a3 a2 b2 c2 a2 c2 b2 ,即 a3 a2,····················································4分
因为 a 0,则 a 1 .·························································································· 5分
(2)由 S 1 ABC bc sin A
3
, A 1,得 bc 3 3 ,·································6分
2 4 3 2 2 4
解得bc 1,·····································································································7分
由a2 b2 c2 2bccos A ,即 a2 b2 c2 bc,即b2 c2 2,·······························8分
由 (b c)2 b2 c2 2bc 4,得b c 2,·························································9分
故 a b c 3,所以 ABC的周长为 3.······························································· 10分
18.解:(1)设等差数列 an 的公差为 d,
a a1 4d 175 17
由题得 S 2a , 即 4 5 ,············································· 2分 4 2 22 4a1 d 2(a1 d ) 22 2
a1 4d 17
整理得 a 2d 11,························································································· 3分 1
a1 5
解得 d 3 , ····································································································· 4分
所以 an 3n 2 .·································································································· 5分
2 {b } a1,1,1,a2 ,1,1,1,1,a3 ,1,1,1,1,1,1,1,1, a k,1 ,1 ,1 ,a k 1, ( )方法一:由题意可知, n 的各项为
2k
5,1,1,8,1,1,1,1,11,1,1,1,1,1,1,1,1, 3k 2,1 , 1 ,1 ,3k 5, 即 ,············································6分
2k
因为 2 22 23 24 25 26 7 133 200 ,
且 2 22 23 24 25 26 27 7 261 200 ,··························································· 8分
所以 a1,a2 ,a3 ,a4 ,a5 ,a6 ,a7 会出现在数列 bn 的前 200项中,
所以 a7前面(包括 a7)共有 126+7=133项,所以 a7后面(不包括 a7)还有 67个 1, ······10分
所以T200 (5 8 11 14 17 20 23) (2 2
2 2 3 2 4 2 5 2 6) 67 291 .················· 12分
方法二:在数列 bn 中, ak前面(包括 ak 共有 2 22 23 24 2 k 1 k 2 k k 2 项,
······················································································································· 6分
令 2k k 2 200 (k 1,2, ),则 k 7,································································8分
所以 a1,a2 ,a3 ,a4 ,a5 ,a6 ,a7 会出现在数列 bn 的前 200项中,
所以 a7前面(包括 a7)共有 126+7=133项,所以 a7后面(不包括 a7)还有 67个 1,····· 10分
所以T200 (5 8 11 14 17 20 23) (2 2
2 2 3 2 4 2 5 2 6) 67 291 .················· 12分
19.解:(1)如图,连接 SO和OE,
因为 S ABCD 是正四棱锥,所以 SO 平面 ABCD,
又因为 BC 平面 ABCD,所以 SO BC ①···························································1分
因为 ABCD是正方形,所以 DC BC ,
又因为点O, E分别是 BD , BC中点,所以OE∥DC ,
所以OE BC ②······························································································ 3分
又因为OE SO O,OE、 SO 平面 SOE,
所以 BC 平面 SOE ,··························································································· 4分
因为OF 平面 SOE,所以OF BC .·····································································5分
(2)易知OB,OC ,OS 两两相互垂直,如图,以点O为原点,OB,OC ,OS为 x, y, z轴建
立空间直角坐标系,
因为四棱锥 S ABCD 的所有棱长为 2 2,所以 BD 4, SO 2,
所以O(0,0,0), S(0,0,2), D( 2,0,0), E(1,1,0),···················································· 6分
设 SF SE(0 1),得 F ( , , 2 2 ),则
SD ( 2,0, 2),DE (3,1,0),OF ( , ,2 2 ) ···················································· 7分
设平面 SDE的法向量为 n (x, y, z),则
n SD 2x 2z 0 z x
,解得 y 3x,取
x 1,得 n (1, 3, 1),·······························9分
n DE 3x y 0
设直线OF 与平面 SDE所 成 角 为
,则
n OF 3 2 2
sin cos n,OF
n OF 11 2 2 (2 2 )2
2
(0 1)
2 ,·········································································· 11分11 6 8 4
8 2 4
当 33时, 6 2 8 4取得最小值 ,此时 sin 取得最大值 .················12分2 6 3 3 11
20. 解:(1)设“主、客队分出胜负时恰进行了 3场比赛”事件为事件 A,则事件 A包含“主队
3场全胜”和“客队 3场全胜”两类事件,······························································ 1分
1 2 1 1
“主队 3场全胜”的概率为 1 1 4 3
1 2
,
8 ········································· 2
分
1 2 1 1
“客队 3场全胜”的概率为 ,···························································· 3分
4 3 2 12
1 1 5
所以 P(A) ,
8 12 24
5
所以主、客队分出胜负时恰进行了 3场比赛的概率为 .··········································· 4分
24
(2)能,理由如下:
设“剩余四场比赛未调整Y 、 Z 出场顺序,客队获胜”为事件M ,第二场单打( X 对阵 A)、
第三场单打( Z 对阵C)、第四场单打(Y 对阵 A)、第五场单打( X 对阵 B)的胜负情况分别
为:胜胜胜、胜负胜胜、胜胜负胜、负胜胜胜;······················································· 5分
P M 2 1 1 2 1 1 1 2 1 2 1 1 1 1 1 11则 ,·························· 7分
3 2 3 3 2 3 2 3 2 3 2 3 2 3 2 36
设“剩余四场比赛调整Y 、Z 出场顺序,客队获胜”为事件 N,第二场单打( X 对阵 A)、第三
场单打(Y 对阵C)、第四场单打( Z 对阵 A)、第五场单打( X 对阵 B)的胜负情况分别为:
胜胜胜、胜负胜胜、胜胜负胜、负胜胜胜;····························································· 8分
P N 2 2 1 2 2 1 1 2 2 3 1 1 2 1 1 12 1则 ,··················· 10分
3 3 4 3 3 4 2 3 3 4 2 3 3 4 2 36 3
因为 P M P N ,·························································································11分
所以客队调整选手Y为三单、选手 Z 为二单获胜的概率更大. ····································12分
21.解:(1)由题知 AF FN ,得 a c 4 c ,······················································ 1分
又因为右焦点为 F (1,0),则 c 1,
解得 a 2,·······································································································2分
所以 b c2 a 2 3,·······················································································3分
2 2
所以椭圆C
x y
的方程为 1 .············································································4分
4 3
y
(2)设点M 0的坐标为 (x0 , y k0 ),则 AM x0 2
,
y
所以直线 AM 的方程是 y 0 (x 2)x 2 ,······························································· 5分0
y 6y当 x 4时, 0x 2 ,0
6y
所以点 P的坐标为 (4, 0 )x 2 ,·············································································· 6分0
6 y0 0 2y y
所以 tan PFN k x0 2 0 , tan MFN kMF 0PF x 1,····························· 7分4 1 x0 2 0
2 2y 0
2 tan PFN x0 2 4(x0 2)y0
所以 tan 2 PFN 2 2y .··································· 8分1 tan PFN 1 ( 0 )2 (x0 2)
2 4 y 20
x0 2
x2 y2 x 2 y 2
因为点M (x0 , y0 )在椭圆 1上,所以 0 0 1,即 4y 20 12 3x
2
0 ,·················9分4 3 4 3
4(x 2)y 4(x 2)y
所以 tan 2 PFN 0 0 0 0(x0 2)
2 4y 20 (x0 2)
2 (12 3x 20 )
4(x0 2)y0 (x0 2)y 0 y0
4x 2
tan MFN
4x 8 (x 1)(x 2) x 1 ,············································ 11分0 0 0 0 0
又因为 PFN 和 MFN是锐角,
所以 MFN 2 PFN .························································································12分
22.解:(1)当 a e, f (x) ln x
1
ex2 1,则 f '(x) ex,······································· 1分
2 x
f '(1) 1故 e 1 e,························································································· 2分
1
x 1时, f (1) ln1
1
e 1 e,故切点为 (1,
1 e),·····················································3分
2 2 2
1 1
所以 f (x)在 x 1处的切线方程为 y e (1 e)(x 1),即 y (1 e)x e 1 .················4分
2 2
(2)函数 f (x)有两个零点
log x 1方程 a ax
2 0在 x (0, )上有两个根
2
ln x 1方程 2 a lna在 x (0, )上有两个根x 2
ln x 1函数 y 2 与 y a ln a的图象在 x (0, )上有两个交点································· 5分x 2
设 g(x)
ln x 1 2ln x
2 ,则 g '(x) x x3
,
g '(x) 1 2ln x 3 0时, 0 x e ; g '(x)
1 2ln x
3 0时,x x x e
,
g(x) ln x所以 2 在 (0, e)上单调递增,在 ( e, )上单调递减,···································6分x
由 g(1) 0, g( e)
1
,当 x 1时, g(x) 0,当 x 时, g(x) 0,作图如下:
2e
······················································································································· 7分
0 1 a lna 1 1由图得 ,即 a ln a 0,··························································· 8分
2 2e e
设 h(x) x ln x(x 0),则 h '(x) 1 ln x,································································ 9分
h '(x) 1 ln x 0 x 1时, ; h '(x) 1 ln x 0时, 0 x
1
;
e e
所以 h(x) x ln x在 (0,
1) 1上单调递减,在 ( , )上单调递增,··································· 10分
e e
因为 0 x 1时 ln x 0,且 h(1) 0,
1
所以当 0 x 1时, h(x) 0;当 x 1时, h(x) 0,········································ 11分
e
又因为 h(x)min h(
1) 1 1 1 1 ,所以 x ln x 0的解集为 (0, ) ( ,1)
e e e e e
综上所述 a (0,
1 1
) ( ,1) .··················································································· 12分
e e