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惠州市 2025 届高三第二次调研考试试题
高三数学参考答案与评分细则
一、单项选择题:本题共8小题,每小题满分5分,共40分.
题号 1 2 3 4 5 6 7 8
答案 B D C B A A D C
1.【解析】因为B x0 x4 , 所以AB x2 x4 . 故选:B.
2.【解析】因为z2 10,即z2 1,所以z i,所以 z1 1i 12 1 2 2 .
故选:D.
9a 36d 27
3.【解析】设等差数列 a 的公差为d ,由已知得: 1 ,解得a 1,d 1,
n a 9d 8 1
1
所以a a 99d 19998.故选:C.
100 1
4.【解析】连接FB,在正方体ABCDABCD 中,BC 平面ABBA ,棱BC的中点为E,
1 1 1 1 1 1
则BE 平面ABBA ,而BF平面ABBA ,故BE BF ,
1 1 1 1
则EFB即为直线EF 与平面ABBA 所成角,
1 1
设正方体棱长为2,则BE 1,BF BF2 BB2 14 5,
1 1
BE 1 6
则 EF BF2BE2 6 ,故sinEFB .故选:B.
EF 6 6
2 5
5.【解析】由 b 2,(2ab)b3,得2ab b 2ab23,即ab ,
2
5
ab a ab 5 3 5
由已知得 a 2,所以向量b在向量a上的投影向量为 a 2 ( 3,1)( ,).
a a a 2 4 8 8
故选:A.
a1 1
6.【解析】若函数 f(x)在(1,)上单调递增,则 ,解得a ,
12a0 2
所以“a0”是“函数 f(x)在(1,)上单调递增”的充分不必要条件.故选:A.
高三数学答案 第1页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}7.【解析】设优弧BC所在圆的圆心为O,半径为 ,连接OA,OB,OC .易知“水滴”的“竖直高度”
OAR 4 5
为OAR,“水平宽度”为2R, 由题意知 ,解得OA R. 因为AB与圆弧相切于点B,
2R 3 3
OB R 3
所以OB AB.在RtABO中, sinBAO ,又BAO(0, ),
OA 5 5 2
R
3
4
所以cosBAO 1sin2BAO ,由对称性知,BAO CAO,则 BAC 2BAO,
5
3 4 24
所以sinBAC 2sinBAOcosBAO 2 .故选:D.
5 5 25
8.【解析】根据已知条件设理科女生有x 人,理科男生有x 人;文科女生有 y 人,文科男生有y 人;
1 2 1 2
根据题意可知:x x y y ,x y x y ,
1 2 1 2 1 1 2 2
根据同向不等式可加的性质有:x x x y y y x y ,即x y ,所以理科女生多于文
1 2 1 1 1 2 2 2 1 2
科男生,C正确.
其他选项没有足够证据论证.
故选:C.
二、多项选择题:本题共3小题,每小题满分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。全部选对得6分,部分选对得部分分,有选错的得0分。
题号 9 10 11
全部正确选项 AD ABD ACD
9.【解析】数据从小到大排列为:1,1,2,3,3,3,3,4,5,5.
对于A,该组数据的极差为514,故A正确;
12234452
对于B,众数为3,平均数为 3,两者相等,故B错误;
10
1
对于C,方差为 (13)22(23)21(33)24(43)21(53)221.8,故C错误;
10
对于D,1080% 8,这组数据的第80百分位数为第8个数和第9个数的平均数4.5,故D正确.
故选:AD.
10.【解析】由图像可知: f x 2, A 2 ;
max
高三数学答案 第2页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}又 f 02sin1,故sin 1 ,又 ,所以 ,所以A项正确;
2 2 6
7 7 7
已知 f 2sin 0,由五点作图法可知: ,解得:2,所以B项正确;
12 12 6 12 6
故 f x2sin2x ;则xf(x )2xsin2x ,设h(x) xf(x )2xsin2x,
6 12 12
则h(x)2(x)sin(2x)2xsin2xh(x),所以函数y xf(x )是偶函数,故C项错误;
12
g(x) f(x )2sin 2(x ) 2sin(2x )2cos (2x )
6 6 6 6 2 6
2cos( 2x)2cos(2x ),所以D项正确;
3 3
故选:ABD.
2
11.【解析】A选项,经验算,点( ,0)和(1,1)的坐标满足曲线L的方程:x2 (y x)2 1,所以点
2
2
(
,0)和(1,1)均在L上,故A项正确;
2
B选项,OP x2 y2 ,因为曲线L:x2 (y x)2 1关于 y轴对称,当x0时,x2 (yx)2 1,
设xcos,yxsin, , ,
2 2
1cos2
所以 OP 2 x2 y2 cos2(cossin)2 1 sin2
2
3 1 3 5 1
sin2 cos2 sin(2),其中tan ,
2 2 2 2 2
3 5 51 3 5 51
所以 OP , OP ,所以 OP 的最大值和最小值之和
min 2 2 2 max 2 2 2
为 5,故B项错误;
C选项,因为曲线L:x2 (y x)2 1关于 y轴对称,当x0时,x2 (yx)2 1,
则(yx)2 1x2,所以y x 1x2 ,因求点P的纵坐标的最大值,故取y x 1x2 ,
1
又 y2 (x 1x2)2 12x 1x2 12 x2(1x2) 1x2 (1x2)2(当且仅当 x2 时
2
等号成立),所以y 2 ,故C项正确;
高三数学答案 第3页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}y2 x2
D选项, PA PB 2 3等价于点P在椭圆 1内(包含椭圆),由B项可知,即满足:
3 2
3(1cos2)
2(cossin)2 3cos26,即2(1sin2) 6,整理得:
2
3
4sin23cos25,即5sin(2)5,其中其中tan ,即sin(2)1恒成立,则故
4
D项正确.
故选:ABD.
三、填空题:本题共3小题,每小题5分,共15分.
5
12. 32 13. 14. e2
5
12.【解析】当x1时,二项式展开式各项的系数和为25 32.故答案为:32.
13.【解析】由题意知 AF ac, FF 2c, FB ca,且三者成等比数列,则 FF 2 AF FB
1 1 2 1 1 2 1 1
1 5 5
即4c2 (ca)(ca)c2 a2,所以e2 ,所以e . 故答案为: .
5 5 5
b 1 b 1
14.【解析】设方程ln(ax ) x2 的实根为x ,则ln(ax ) x2 ,
2 4 0 0 2 0 4
b x2 1 b x2 1
所以ax e 0 4 ,即ax e 0 4 0.
0 2 0 2
y x2 1
设点P(a,b),则点P在直线x x e 0 4 0上.
0 2
x2 1
设点O(0,0)到直线x x y e x 0 2 1 4 0的距离为d ,则d e 0 4 ,
0 2 x2 1
0 4
1 et 1 et(t1)
设t x2 , f(t) (t ),则 f'(t) ,
0 4 t 2 t2
1
求得 f(t)在 ,1 上单调递减,在 1, 上单调递增,所以 f(t) f(1)e,
2 min
则d f(t)e,又a2 b2 OP 2,由几何意义可知 OP d ,所以a2 b2 OP 2 e2.
高三数学答案 第4页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#} 3
3 b a e
3 a e0 2
检验:当t 1时,x ,由 2 2 ,解得 ;
0 2 e
a2 b2 e2
b
2
3
3 b a e
a e0
2
由 2 2 ,解得 ,所以则a2 b2可以取到最小值e2.
e
a2 b2 e2
b
2
故答案为:e2.
四、解答题:本题共5小题,共77分.解答应写出文字说明、证明过程或演算步骤.
15.(本小题满分13分,其中第一小问6分,第二小问7分。)
1 1 1
【解析】(1)因为: f 1 10 ,所以切点坐标为:1, ,···························1分
2 2 2
2
又 fx x1 , ·····························································································2分
x
所以 f12, ································································································3分
即所求切线的斜率为2.
1
所以切线方程为:y 2x1, ······································································· 5分
2
化简得:4x2y30,
所以曲线y f x在点(1,f 1)处的切线方程为4x2y30.
··························································································································6分
3
【注】切线方程写成 y 2x 不扣分
2
2 x2x2 x2x1
(2) fxx1 ,(x0) ········································8分
x x x
由 f'(x)0得x2;由 f'(x)0得0 x2. ············································10分
所以 f x在 1,2 上单调递减,在 2,e 上单调递增. ·················································11分
所以函数 f x在区间 1,e 上的极小值为 f 22ln2,也是最小值.
所以函数 f x在区间 1,e 上的最小值为2ln2.
························································································································ 13分
高三数学答案 第5页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}16.(本小题满分15分,其中第一小问5分,第二小问10分。)
【解析】(1)证明:已知PA底面ABCD,且BC底面ABCD,
所以PABC. ···································································································2分
由ACB90,可得BC AC .············································································3分
又PAAC A,PA,AC 平面PAC , ·································································4分
所以BC 平面PAC . ······················································································ 5分
(2)取CD的中点E.由AB∥CD,BAD 120,可得ADC 60,
又因为AD CD 1,所以三角形ADC是正三角形,·················································6分
故 AE CD, AE AB. ··················································································7分
在RtACB中,BAC 60,AC 1,所以AB 2. ·············································8分
可建立如图所示的空间直角坐标系,
3 1 3 1
求得A 0,0,0 ,P 0,0, 3 ,C , ,0,D , ,0,B 0,2,0 ,························ 9分
2 2 2 2
3 3
由(1)可知,BC ( , ,0)是平面PAC的一个法向量,·····································10分
2 2
DCn0
设平面PDC的一个法向量为n(a,b,c),则 ,
PCn0
b0
即
3 1
, ··················································································11分
a b 3c0
2 2
3
令a 3,得n( 3,0, ), ···········································································12分
2
设平面PCD与平面PCA的夹角为,
3
BCn
5
2
所以cos cos BC,n .
BC n 15 5
3
2
5
所以平面PCD与平面PCA夹角的余弦值为 .
5
························································································································ 15分
高三数学答案 第6页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}BCn
【注】写出公式cos cos BC,n 给一分,代入数据给一分,结果计算正确给一分
BC n
17.(本小题满分15分,其中第一小问7分,第二小问8分。)
x2 y2 1
【解析】(1)直线l与双曲线C有两个不同的交点,则方程组 有两组不同的实数根,
y kx1
整理得(1k2)x2kx20. ···············································································2分
1k2 0
,··············································································4分
4k24(1k2)(2)0
解得 2 k 2 且k 1, ··········································································6分
双曲线C与直线l有两个不同的交点时,k的取值范围是( 2,1)(1,1)(1, 2).
··························································································································7分
(2)解法一:设交点A(x ,y ),B(x ,y ),
1 1 2 2
由(1)知双曲线C与直线l联立的方程为(1k2)x2kx20.
2k 2
由韦达定理得:x x ,x x ,···················································· 8分
1 2 1k2 1 2 1k2
则 AB 1k2 x x 1k2 (x x )2 4x x ··············································9分
2 1 2 1 1 2
2k 2 84k2
1k2 ( )2 4( ) 1k2 ········································10分
1k2 1k2 1k2
1
又O到直线l的距离d , ········································································11分
1k2
1 2k2
所以OAB的面积S AB d 2,·············································12分
OAB 2 1k2
6
解得k 0或k , ··················································································14分
2
6
又因为 2 k 2 且k 1,所以k 0或k .
2
6
所以当k 0或k 时,OAB的面积为 2 . ··················································15分
2
高三数学答案 第7页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}【注】漏掉k 0扣一分
解法二:设交点A(x ,y ),B(x ,y ),直线l与y轴交于点D(0,1),
1 1 2 2
由(1)知双曲线C与直线l联立的方程为(1k2)x2kx20.
2k 2
由韦达定理得:x x ,x x ,···················································· 8分
1 2 1k2 1 2 1k2
1 1
当A,B在双曲线的一支上且 x x 时,S S S (x x ) x x ;
1 2 OAB OAD OBD 2 1 2 2 1 2
1 1
当A,B在双曲线的两支上且x x 时,S S S (x x ) x x
1 2 OAB OAD OBD 2 1 2 2 1 2
1
综上,S x x . ················································································10分
OAB 2 1 2
【注】未讨论两种情况、直接写对面积公式的扣一分
1
由已知得S x x 2 ,故(x x )2 8,即(x x )2 4x x 8
OAB 2 1 2 1 2 1 2 1 2
2k 2
所以( )24( )8,········································································· 12分
1k2 1k2
6
解得k 0或k ,·······················································································14分
2
6
又因为 2 k 2 且k 1,所以k 0或k .
2
6
所以当k 0或k 时,OAB的面积为 2 .···················································15分
2
18.(本小题满分17分,其中第一小问10分,第二小问7分。)
【解析】(1)由abc,则A BC. ······························································· 1分
由ABC ,则ABC 3A,故0 A , ··············································2分
3
所以0 tan A 3, ·························································································· 3分
因为tan A为整数,所以tan A1, ········································································4分
3
解法一:由tan A1,可得A ,BC . 因为A BC,所以B为锐角,
4 4
则 B ,所以 C ,············································································ 6分
4 2 4 2
所以角A,B,C均为锐角,所以tan A,tanB,tanC 均为正整数,
又tan A1,所以tanC tanB2,
高三数学答案 第8页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}3 1tanC
由tanB tan( C) 2,································································8分
4 1tanC
解得tanC 3,所以tanB 2,tanC 3.
综上,tan A1,tanB 2,tanC 3.
tan AtanB 12
经检验,当tan A1,tanB 2时,因为tan(AB) 3tanC
1tan AtanB 112
所以ABC ,符合题意. ··············································································10分
【注】未检验扣一分
3
解法二:由tan A1,可得A ,BC .
4 4
3 3
因为 A BC ,所以 BC 2B,则 B ,
4 4 8
3
所以1 tanB tan . ···················································································6分
8
3
2tan
3
8
3 3
由tan 1,则tan2 2tan 10 ,
4 3 8 8
1tan2
8
3 3
解得tan 1 2或tan 1 2(舍去),
8 8
故1tanB1 2 , ························································································8分
又21 2 3,tanB为正整数,所以tanB 2,··················································9分
tan AtanB 12
所以tanC tan(AB) 3,
1tan AtanB 112
综上,tan A1,tanB 2,tanC 3. ····································································10分
2 5 10 3 10
(2)由(1)可知,tanB 2,tanC 3,则sinB ,cosC ,sinC ,
5 10 10
························································································································ 12分
a b c
在ABC中,由正弦定理 sinB sinC ,
sin
4
asinB 2 10a asinC 3 5a
b c
可得 5 , 5 ,····················································14分
sin sin
4 4
1 10a
又AC 的中点为D,所以CD b ,
2 5
高三数学答案 第9页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}在ABC中,由余弦定理得:BD2 CD2 CB2 2CDCBcosC
10 10 10
( a)2 a2 2 aa ······································································15分
5 5 10
a2
所以BD a,····································································································16分
10
所以cosCDB cosC .
10
························································································································ 17分
19.(本小题满分17分,其中第一小问4分,第二小问7分,第三小问6分。)
【解析】(1)因为 a 是12项01数列,当且仅当n3p(pN, p4)时,a 0,
n n
所以当n3p2和n3p1(pN, p4)时,a 1. ··········································1分
n
设数列 (1)na 的所有项的和为S,
n
则S (1)a (1)2a (1)4a (1)5a (1)7a (1)8a (1)10a (1)11a ······2分
1 2 4 5 7 8 10 11
(1)(1)2 (1)4 (1)5 (1)7 (1)8 (1)10 (1)11
(1)11(1)(1)11(1)
0
所以数列 (1)na 的所有项的和为0. ·····································································4分
n
(2)①证明:因为数列 a , b 是从集合M 中任意取出的两个数列,
n n k
所以数列 a , b 为k项01数列,
n n
所以X 的可能取值为:1,2,3,,k . ········································································5分
因为集合M 中元素的个数共有C0 C1 C2 Ck 2k 个,····································6分
k k k k k
当X m(m1,2,,k)时,则数列 a , b 中有m项取值不同,有km项取值相同,
n n
高三数学答案 第10页,共11页
{#{QQABLQAAogAgAgAAAQgCQQkwCgCQkhCCAQgOwFAIIAIAyBFABAA=}#}Cm2k
k
所以 A2 Cm , ····················································7分
P(X m) 2 k (m1,2,,k)
C2 2k 1
2k
所以随机变量X 的分布列为:
X 1 2 3 …… k
C1 C2 C3 Ck
P k k k …… k
2k 1 2k 1 2k 1 2k 1
··························································································································8分
mk! (k1)!
因为mCm k kCm1(mN,1mk),
k m!(km)! (m1)! (k1)(m1) ! k1
··························································································································9分
C1 C2 Ck 1
所以E(X)1 k 2 k k k (1C1 2C2 3C3 kCk)
2k 1 2k 1 2k 1 2k 1 k k k k
k k2k1 k2k1 k
(C0 C1 C2 Ck1) ,
2k 1 k1 k1 k1 k1 2k 1 2k 2
k
即E(X) . ··································································································11分
2
P(AB) P(AB) P(B)P(AB)
②解:由条件P B A P B A 得: ,··················12分
P(A) P(A) 1P(A)
所以P(AB)1P(A) P(A) P(B)P(AB) ,
化简得:P(AB) P(A)P(B),·············································································14分
所以P(AB)P(B)P(AB) P(A)P(B)P(B)P(AB),
则P(AB)1P(B) P(B) P(A)P(AB)
即P AB P B P B P AB ,·········································································16分
所以 P AB P AB ,即P A|B P A|B .
P B P B
························································································································ 17分
高三数学答案 第11页,共11页
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