巴中市普通高中 2023 级“零诊”数学试题
参考答案
一、单选题: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 D B B C C D B
二、多选题: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
BC ACD AB
三、填空题:本题共 3 小题,每小题 5 分,共 15分.
题号 12 13 14
答案
1 1 e2
24 1,
4 e2 4
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.(13 分)
3a a
解析:(1)在等差数列 {a } 中: S 1 3 3a 9 ,
n 3 2 2
则 a 3 , a 2a 39·······························································3 分
2 5 2
公差 d a 5 a 2 93 2,a a (n2)d 3(n2)22n1··················5 分
52 3 n 2
故数列
{a }
的通项公式为:a 2n1··············································6 分
n n
高2023级“零诊”数学参考答案 第 1 页(共 7 页)1 1 1 1 1
(2)由(1)得: b ···················8 分
n a a (2n1)(2n1) 22n1 2n1
n n1
则T b b b b
n 1 2 3 n
1 1 1 1 1 1 1 1 1 1 1 1 1 1
= (1 )+ ( )+ ( )++( )+( )
2 3 2 3 5 2 5 7 2 2n3 2n1 2 2n1 2n1
1 1 1 1 1 1 1 1 1 1
= (1 )
2 3 3 5 5 7 2n3 2n1 2n1 2n1
1 1
= (1 )··································································12 分
2 2n1
1
由于 nN*,则: T ························································13 分
n 2
16.(15 分)
解析:(1)在直三棱柱ABC ABC 中,BB平面ABC,BC面ABC,则
1 1 1 1
BBBC
1
又ABC90,即ABBC ,又B
1
BABB
所以BC 平面ABB ··················································································2 分
1
又AB 平面ABB ,所以BC AB
1 1 1
在直三棱柱ABC ABC 中,AA AB,则四边形ABB A 为正方形
1 1 1 1 1 1
所以AB AB,又BCABB,所以AB 平面ABC ······································4 分
1 1 1 1 1
又AC 平面ABC,所以AC AB ·····························································6 分
1 1 1 1
高2023级“零诊”数学参考答案 第 2 页(共 7 页)(2)由(1)知BA,BC,BB 两两互相垂直,
1
故以 所在直线分别为 轴建立如图所示的空间直角坐标系,
BA,BC,BB x,y,z
1
由于AC 2AB,设AB AA 1 2,则 BC 2 3 ,
B 0,0,0 ,A 2,0,0 ,C 0,2 3,0 ,B 0,0,2 ,A 2,0,2 ,E 1, 3,2 ·································9 分
1 1
设平面 EBC 的法向量为m x,y,z , B C 0,2 3,0 , B E 1, 3,2
mBC 2 3y0
则: ,取 z1,则y=0,x2 ,得m 2,0,1 ····················11分
mBE x 3y2z0
由(1)知AB 平面ABC ,则平面ABC 的一个法向量为AB 2,0,2 ··················12 分
1 1 1 1
由图可知二面角A BCE的平面角为锐角,记为.
1
2212
3 10
则: cos cos m,AB ··········································· 14 分
1
41 44 10
3 10
即二面角A BCE的余弦值为 ························································15 分
1
10
17.(15 分)
解析:(1)表中数据入下:
语文成绩
数学成绩 合计
不优秀 优秀
优秀 48 36 84
不优秀 24 12 36
合计 72 48 120
··········································································································2 分
高2023级“零诊”数学参考答案 第 3 页(共 7 页)零假设为H :数学成绩与语文成绩无关联;
0
120(48123624)2 20
根据表中数据,计算得到2 0.95246.635x .
72488436 21 0.010
··········································································································4 分
依据小概率值0.010的独立性检验,没有充分证据推断出H 不成立,因此
0
可以认为H 成立,即认为数学成绩与语文成绩无关联;
0
··········································································································6 分
(2)由题意得分层随机抽样比为
4:3
,
则语文成绩不优秀、优秀的学生分别抽取4人,3人
CkC3k
X 的取值可能为 0,1,2,3, PX k 3 4 ,k 0,1,2,3·······················8 分
C3
7
则X的分布列为:
X 0 1 2 3
P 4 18 12 1
35 35 35 35
········································································································ 10 分
4 18 12 1 9
数学期望为: EX0 1 2 3 ································12 分
35 35 35 35 7
9 4 9 18 9 12 9 1 24
方差为: DX(0 )2 (1 )2 (2 )2 (3 )2
7 35 7 35 7 35 7 35 49
········································································································ 15 分
18.(17 分)
解析:(1) f '(x)x3ax2bx2,
f '(1)0 a2
由已知: ,得: ···························································3 分
f '(2)0 b1
高2023级“零诊”数学参考答案 第 4 页(共 7 页)此时, f '(x)x32x2x2(x1)(x1)(x2),
令 f '(x)0,得:x1或1<x2; f '(x)0,得:1x1或x2;
f(x)在x1处取得极大值;在x2处取得极小值,符合题意,
故a2,b1····················································································5 分
1 2 1
(2)由(1)知: f(x) x4 x3 x22xc,则 f '(x)(x1)(x1)(x2)
4 3 2
易得 f(x)在[0,1]上单调递增,在[1,2]上单调递减,在[2,3]上单调递增.
····································································································7 分
f(0)c,f(1)13c,f(2)2c,f(3)15c,
12 3 4
f(x) maxf(1), f(3) f(3) 15cM,
max 4
f(x) minf(0), f(2) f(0)cm, ·····················································9 分
min
19
又因为Mm 15c c ,即: 4c2+15c190 ,
4 4
又 c0,所以:c1·········································································11分
(3)因为g(x)在[0,3]上单调递减,则在[0,3]上g'(x) f '(x)k≤0,g'(x)0仅在端点处
成立.·································································································13 分
即k≥f '(x) x32x2 x2在[0,3]上恒成立·············································14 分
k≥f '(x) max f '(0), f '(3) max 2,8 8.·············································16 分
max
即k的取值范围为:[8,).·······························································17 分
高2023级“零诊”数学参考答案 第 5 页(共 7 页)19.(17 分)
b 1
a 2
解析(1)由已知: 2c2 5 ·································································2 分
a2 b2 c2
a2
x2
解得: b1 ,则双曲线C的方程为: y2 1····································4 分
4
c 5
yxt
(2)联立方程 ,消x得: 3x2 8tx4t2 40
x2 4y2 40
64t212(4t24)16(t23)0 ,t 3或t 3 ······································ 6 分
8t
设 Ax ,y ,Bx ,y ,则: x 1 x 2 3 ················································7 分
1 1 2 2
x x
4t2 4
1 2 3
则: AB 112 x x 2 x x 2 4x x
1 2 1 2 1 2
16(t2 3) 4 2
2 ····························································9 分
3 3
解得:t 2满足0,所以t 2······················································10 分
(3)设 Ax ,y ,Bx ,y ,M x ,y
1 1 2 2 0 0
设在 A 处的切线方程为:yk(xx ) y ,代入x2 4y2 4得
1 1 1 1
(14k2)x2 8k(y kx )x4(y kx )2 40,令0,整理得
1 1 1 1
(x2 4)k2 2x yk y2 10,解关于k的二次方程,其
1 1 1 1
高2023级“零诊”数学参考答案 第 6 页(共 7 页)2x y x y x
4x2y2k4(x2 4)(y2 1)16y2 4x2 160,则k 1 1 1 1 1 ,
1 1 1 1 1 1 2(x2 4) 4y2 4y
1 1 1
··································································································13 分
x x2
所以曲线 C在 A 处的切线方程为: y y 1 xx ,又 1 y2 1 ,得:
1 1 1
4y 4
1
x x4y y4;同理,曲线C在 B 处的切线方程为:x x4y y4···················· 15 分
1 1 2 2
x x 4y y 4
又 Mx ,y 为两切线的交点,则: 1 0 1 0
0 0 x
2
x
0
4y
2
y
0
4
即A、B都在直线x x4y y4上,又A、B都在直线ykx3k 上,
0 0
4
而 ykx3k 过定点3,0,所以 3x 4 , x ········································16 分
0 0
3
4
综上,点M 的轨迹方程为: x ······················································17 分
3
x2 x x
注:另法1:对 y2 1求导得: 2yy'0,即y' ,则在A处的切线方
4 2 4y
x
程k 1
4y
1
x x
另法2:直接写出曲线C在 A 处的切线方程为: 1 y y1,即x x4y y4;
1 1 1
4
x x
曲线C在 B 处的切线方程为: 2 y y1,即x x4y y4请酌情考虑扣分。
2 2 2
4
高2023级“零诊”数学参考答案 第 7 页(共 7 页)