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2024 年高三年级第一次适应性检测
数学参考答案及评分标准
一、单项选择题:本题共8小题,每小题5分,共40分.
1--8:ADBA CCBA
二、多项选择题:本题共3小题,每小题6分,共18分.
9.AB 10.AC 11.BCD
三、填空题:本题共3个小题,每小题5分,共15分.
51
12.0; 13. ; 14.1 7.
2
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)
解:(1)由题知:各组频率分别为:0.15,0.25,0.3,0.2,0.1······················3分
日均阅读时间的平均数为:
300.15500.25700.3900.21100.167(分钟)······················· 6分
(2)由题意,在[60,80),[80,100),[100,120]三组分别抽取3,2,1人·······················7分
的可能取值为:0,1,2·················································································8分
C3C0 1
则P(0) 4 2 ················································································9分
C3 5
6
C2C1 3
P(1) 4 2 ···············································································10分
C3 5
6
C1C2 1
P(2) 4 2 ·············································································· 11分
C3 5
6
所以的分布列为:
0 1 2
1 3 1
P
5 5 5
1 3 1
E()0 1 2 1······································································13分
5 5 5
16.(15分)
x2 x1
解:(1)当a1时, f (x) , f (x ) 1解得x 1························3分
x 0 0
1 3
又因为 f(1) ,所以切线方程为:x y 0···········································5分
2 2
x2 ax1
(2) f(x)的定义域为(0,), f (x) ········································6分
x
当a0时,得 f(x)0恒成立, f(x)在(0,)单调递增·································8分
数学评分标准 第1页(共5页)
{#{QQABYYCEggigAhBAAQgCEwEICEKQkAACACoOQEAAoAAAyQNABCA=}#}当a 0时,令g(x) x2 ax1, a2 4····················································9分
(ⅰ)当0即0a2时,
f(x)0恒成立, f(x)在(0,)单调递增·········································· 11分
a a24 a a24
(x )(x )
(ⅱ)当 0即a 2时, f(x) 2 2 ···············12分
x
a a2 4 a a2 4
由 f(x)0得,0 x 或x ,
2 2
a a2 4 a a2 4
由 f(x)0得, x
2 2
a a2 4 a a2 4
所以 f(x)在(0, ),( ,)单调递增,
2 2
a a2 4 a a2 4
在( , )单调递减···········································14分
2 2
综上:当a2时, f(x)在(0,)单调递增;
a a2 4 a a2 4
当a 2时, f(x)在(0, ),( ,)单调递增;
2 2
a a2 4 a a2 4
f(x)在( , )单调递减·······················15分
2 2
17.(15分)
解:(1) 取棱AA中点D,连接BD,因为AB AB ,所以BD AA ·················1分
1 1 1
因为三棱柱ABC ABC ,所以AA //BB ······················································2分
1 1 1 1 1
所以BD BB ,所以BD 3·····································································3分
1
因为AB2,所以AD1,AA 2;
1
因为AC 2,AC 2 2 ,所以AC2 AA2 AC2 ,所以AC AA ,············4分
1 1 1 1
同理AC AB,·························································································5分
因为AA AB A,且AA,AB平面AABB ,所以AC 平面AABB ,
1 1 1 1 1 1
因为AC 平面ABC, z
所以平面AABB 平面ABC ··············6分 A B
1 1 1 1
(2)取AB中点O,连接A
1
O, C
1
取BC中点P,连接OP,则OP// AC, D
由(1)知AC 平面AABB ,
1 1
O
所以OP平面AABB ·······················7分 A
1 1
B y
因为AO平面AABB ,AB平面AABB ,
1 1 1 1 1 M P
所以OP AO,OP AB, C x
1
因为AB AA AB ,则AO AB······························································8分
1 1 1
数学评分标准 第2页(共5页)
{#{QQABYYCEggigAhBAAQgCEwEICEKQkAACACoOQEAAoAAAyQNABCA=}#}以O为坐标原点,OP,OB,OA 所在的直线为x轴、 y 轴、z轴,建立如图所示的空
1
间直角坐标系Oxyz,则A(0,1,0),A(0,0, 3),B (0,2, 3),C(2,1,0),
1 1
设点N(a,0, 3),(0a2)···········································································9分
AB (0,2,0),AC (2,1, 3),AN (a,1, 3),
1 1 1 1
nAB 0 2y 0
设面ABC的法向量为n(x,y,z),得 1 1 ,得 ,
1 1 nAC 0 2x y 3z 0
1
取x 3,则 y 0,z 2,所以n( 3,0,2)·············································10分
设直线AN 与平面ABC所成角为,
1 1
|nAN | 3 a2
则sin|cosn,AN |
|n|| AN | 7 a2 4
3 (a2)2
7 a2 4
3 a2 4a4
································11分
7 a2 4
21
若a 0,则sin ,·········································································12分
7
3 4 3 4 42
若a0,则sin 1 1 ,·······························13分
7 4 7 4 7
a
a
4
当且仅当a ,即a 2时,等号成立,·······················································14分
a
42
所以直线AN 与平面AMB所成角的正弦值的最大值 ·································15分
1 7
18.(17分)
解: (1)设M(x,y),切点为N ,则|MN |2|MW |2|OM |2 |OW |2 ,
所以|x2|2 x2 y2 4··············································································3分
化简得 y2 4x,所以C的方程为: y2 4x···················································· 4分
(2)(ⅰ)因为l //l ,所以可设GAGA,GBGB ,
1 2
1
又因为GE (GAGB) (GAGB)GF,
2 2
所以G,E,F 三点共线,同理,H,E,F三点共线,
所以G,E,H 三点共线···················································································6分
(ⅱ)设A(x ,y ),B(x ,y ),A(x ,y ),B(x ,y ) ,AB中点为E,AB中点为F ,
1 1 2 2 3 3 4 4
数学评分标准 第3页(共5页)
{#{QQABYYCEggigAhBAAQgCEwEICEKQkAACACoOQEAAoAAAyQNABCA=}#}将x ym代入 y2 4x得: y2 4y4m0,所以 y y 4,y y 4m,
1 2 1 2
y y
所以 y 1 2 2,同理 y 2(G,E,H,F 均在定直线y 2上)················8分
E 2 F
因为TT//l ,所以EAT 与EAH 面积相等,EBT与EBH 面积相等;
1
所以四边形GTET面积等于四边形GAHB 面积··············································· 10分
设G(x ,2),H(x ,2),
G H
y y y y y2
直线AA: y y 1 3 (xx ) ,即 y y 1 3 (x 1 ),
1 x x 1 1 y2 y2 4
1 3 1 3
4 4
4x y y 2(y y ) y y
整理得:直线AA: y 1 3 ,又因为 y 2,所以x 1 3 1 3 ,
y y G G 4
1 3
4x y y 2(y y ) y y
同理,直线BA: y 2 3 , y 2,所以x 2 3 2 3 ·············12分
y y H H 4
2 3
y y
(y y )( 3 4 y )
(y y )(2y ) 1 2 2 3
所以|GH ||x x | | 1 2 3 | | |
G H 4 4
|(y y )(y y )|
1 2 3 4 ····························14分
8
1 (y y )2| y y |
所以四边形GAHB 面积S |GH || y y | 1 2 3 4
2 1 2 16
[(y y )24y y ] (y y )24y y
1 2 1 2 3 4 3 4
16
(1616m) 1616n
16
4 (1m)2(1n)
(1m)2 1n
4[ ]2(2m2 2mn)16············16分
2
m2 2mn m1
当且仅当(1m)2 1n,即 ,即 时取等号,
nm2 2m6 n3
所以GAT 面积的最大值为16······································································17分
数学评分标准 第4页(共5页)
{#{QQABYYCEggigAhBAAQgCEwEICEKQkAACACoOQEAAoAAAyQNABCA=}#}19.(17分)
解:(1)因为m x3 (ab a b a b a b )x3 ,
4 1 4 2 3 3 2 4 1
所以m ab a b a b a b ··································································· 4分
4 1 4 2 3 3 2 4 1
(2)因为 f({a }{b }) f({a }) f({b }) ,
n n n n
所以 f({a }) f({b }) f({c }) f({a }{b }) f({c }) f(({a }{b }){c }) ,
n n n n n n n n n
又因为 f({a }) f({b }) f({c }) f({a })[f({b }) f({c })]
n n n n n n
f({a }) f({b }{c })
n n n
f({a }({b }{c }))
n n n
所以 f(({a }{b }) f{c }) f({a }({b } f{c }))
n n n n n n
所以({a }{b }){c }{a }({b }{c }) ···············································10分
n n n n n n
(3)对于{a },{b }S ,
n n
因为(a a xa xn1)(b b xb xn1)d d xd xn1
1 2 n 1 2 n 1 2 n
所以d xn1 a (b xn1)a xk1(b xnk)a xn2(b x)a xn1b ,
n 1 n k n1k n1 2 n 1
所以d ab a b a b a b a b ,
n 1 n 2 n1 k n1k n1 2 n 1
n
所以{a }{b }{d }{a b }····························································13分
n n n k n1k
k1
200 100 200 100 100 (k1)2 1
d a b a b a b a b ·········14分
200 k 201k k 201k k 201k k 201k k(k 1)2k2
k1 k1 k101 k1 k1
100 1 2 1
所以d (1 )
200 2k2 k k 1
k1
100 1 100 1 1
[ ]
2k2 k2k1 (k1)2k2
k1 k1
1 102 1
········································································17分
2 1012102 2
数学评分标准 第5页(共5页)
{#{QQABYYCEggigAhBAAQgCEwEICEKQkAACACoOQEAAoAAAyQNABCA=}#}