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2024-2025 学年第一学期 10 月六校联合调研参考答案及评分标准
高二数学
一、单项选择题
1、B 2、A 3、C 4、B 5、C 6、C 7、D 8、C
二、多项选择题
9、ABD 10、AC 11、BCD
三、填空题
2 4 5
12、 13、 14、4
5 5
四、解答题
15解:(1)因为bsin2A=asinB,所以2bsinAcosA=asinB.
根据正弦定理,得2sinBsinAcosA=sinAsinB, ……………… 2分
因为sinB≠0,sinA≠0,所以cosA=1 . ………………… 4分
2
又A∈(0,π),所以A=π. ………………… 6分
3
1 1 3 3 3
(2)在VABC中,由已知S bcsinA bc ,bc6, ············8分
ABC
2 2 2 2
π
因为A ,a 7
3
1
由余弦定理可得a2 b2 c2
2bccosA,即7bc22bc2bc
,··············10分
2
即7bc2 3bc,又b0,c0所以bc5.
所以VABC的周长周长为5 7.····································································13分
16解:
(1)证明:因为PA是一条母线,所以PA平面ABC,
而BC平面ABC,则PABC,··································································· 2分
因为AB是底面一条直径,C是AB 的中点,所以ACB90,即AC BC,··········4分
又PA,AC平面PAC且PAAC A,
所以BC 平面PAC,而BC平面PBC,则平面PAC 平面PBC.·······················6分
试卷第1页,共5页
{#{QQABLQQEoggoABAAAAhCAQ1yCAOQkhGAAagOhBAEsAAASANABAA=}#}(2)设PA2AB4,则PB2 5,
因为C是AB 的中点,O为底面圆心,所以CO平面PAB,
作OE PB,交PB于点E连接CE,
由OEPB,CE PB可知,CEO是二面角APBC的平面角.·······················10分
4 2 5 3 5
则PBOEPABO,即OE ,在直角COE中,CE OC2OE2 .
2 5 5 5
2 5
5 2
所以 cosCEO .
3 5 3
5
2
故二面角APBC的余弦值为 .··································································15分
3
1
pq
3
17解:(1)由题意得 ,·······························································4分
1
(1 p)q
6
2 1
解得 p ,q .··························································································6分
3 2
(2)比赛结束后,甲、乙个人得分可能为0,2,3,5.
记甲得分为i分的事件为C i0,2,3,5,乙得分为i分的事件为D i0,2,3,5,
i i
C,D 相互独立,
i i
记两轮投篮后甲总得分不低于8分为事件E,
则EC D C D C D ,且C D ,C D ,C D 彼此互斥.
3 5 5 3 5 5 3 5 5 3 5 5
1
易得P(C )= ,························································································8分
3
6
3 2 1 1 3 2 1
P(D )=(1 ) ,P(C )= ,P(D )= ,
3 5 5
4 3 6 3 4 3 2
所以P(E) P(C D C D C D ) P(C D )P(C D )P(C D )
3 5 5 3 5 5 3 5 5 3 5 5
1 1 1 1 1 1 11
= .
6 2 3 6 3 2 36
11
所以两轮投篮后,甲总得分不低于8分的概率为 .·········································15分
36
试卷第2页,共5页
{#{QQABLQQEoggoABAAAAhCAQ1yCAOQkhGAAagOhBAEsAAASANABAA=}#}18解:(1)法1:(待定系数法)
设圆M的方程为 xa 2 yb 2 r2,
因为圆M过点A(3,3),所以 3a 2 3b 2 r2①,······································2分
又因为圆心M在直线2x y50上,所以2ab50②,·······························4分
a2b5
直线x2y50与圆M相切,得到r ③,·······································6分
5
由①②③解得:a2,b1,r 5因此圆M的方程为(x2)2(y1)2 5.······· 7分
法2:(几何性质)
因为直线2x y50与直线x2y50垂直,
2x y50 x 1
又因为圆心M在直线2x y50上,联立方程 ,解得 ·········4分
x2y50 y 3
设两直线的交点为B(1,3),由圆的几何性质,点B(1,3)在圆上,且为直线与圆的切点,
又因为圆M过点A(3,3),且所以圆心M在直线x2上,又圆心M也在直线2x y50上,
x2 x 2
联立方程 ,解得 ,故圆心M(2,1),····································6分
2x y50 y 1
所以半径r AM 5,因此圆M的方程为(x2)2 (y1)2 5.······················7分
(2)设A(x,y),因为A为线段BD的中点,所以B(2x,2y2),
24
x
(x2)2 (y1)2 5 x0 13
因为A,B在圆M上,所以 ,解得 或 ········12分
(2x2)2 (2y1)2 5 y 0 y- 16
13
当A(0,0)时,直线l的方程为x0;···························································· 14分
24 16 5
当A( ,- )时,故直线l的方程为y x2,即5x12y240.··················16分
13 13 12
综上,直线l的方程为x0或5x12y240.···············································17分
试卷第3页,共5页
{#{QQABLQQEoggoABAAAAhCAQ1yCAOQkhGAAagOhBAEsAAASANABAA=}#}x2 y2 1 c 1
19解:(1)由于椭圆C: 1(ab0)的离心率为 ,故 ,
a2 b2 2 a 2
又 AF ac6,所以a4,c2,b2 a2c2 12,
1 2
x2 y2
所以椭圆C的方程为 1.······································································4分
16 12
(2)(i)设l与x轴交点为D,由于直线l交椭圆C于P、Q两点(P、Q在x轴的两侧),
故直线l的的斜率不为0,直线l的方程为xmyt,
xmyt
联立x2 y2 ,则(3t24)y26mty3m2480 ,
1
16 12
则48(12t2m216)0 ,
6mt 3m248
设P(x,y ),Q(x ,y ),则y y ,y y ,······························ 6分
1 1 2 2 1 2 3t24 1 2 3t24
又A(4,0),A (4,0),
1 2
y y y2 y2 3
kk k k 1 1 1 1
故 1 2 PA1 PA2 x 4 x 4 x2 16 4 4 ,·····································10分
1 1 1 y2
3 1
3
(ii)由(i)得k k k k .
3 4 QA1 QA2 4
5 3 3 5 3 k k 5
因为k k k k ,则 (k k ), 2 3 (k k ).
1 4 3 2 3 4k 4k 3 2 3 4 k k 3 2 3
2 3 2 3
9 9
又直线l交与x轴不垂直可得k k 0,所以k k ,即k k .········13分
2 3 2 3 20 PA2 QA2 20
y y 9
所以 1 2 ,20y y 9(ty m4)(ty m4)0,
x 4 x 4 20 1 2 1 2
1 2
于是(9t220)y y 9t(m4)(y y )9(m4)2 0,
1 2 1 2
3m248 6mt
(9t220) 9t(m4) 9(m4)2 0 ,
3t24 3t24
整理得m23m40,解得m1或m4,··················································15分
试卷第4页,共5页
{#{QQABLQQEoggoABAAAAhCAQ1yCAOQkhGAAagOhBAEsAAASANABAA=}#}3m248
因为P、Q在x轴的两侧,所以y y 0,4m4,························ 16分
1 2 3t24
又m1时,直线l与椭圆C有两个不同交点,
因此m1,直线l恒过点D(1,0).································································ 17分
试卷第5页,共5页
{#{QQABLQQEoggoABAAAAhCAQ1yCAOQkhGAAagOhBAEsAAASANABAA=}#}