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1南京市2025届高三年级学情调研数学参考答案2024.09一、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,请把答案填涂在答题卡相应位置上.12345678DDABACCB二、选择题:本大题共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,请把答案填涂在答题卡相应位置上.全部选对得6分,部分选对得部分分,不选或有错选的得0分.91011ABBCDACD三、填空题:本大题共3小题,每小题5分,共15分.请把答
案填写在答题卡相应位置上.12.24013.3π14.33四、解答题:本大题共5小题,共77分.请在答题卡指定区域内作答,解答时应写出必要的文字说明,证明过程或演算步骤.15.(本小题满分13分)解:(1)假设H0:8点前到单位与方案选择无关,则χ2=
100×(28×30-12×30)240×60×42×58······································································2分=800203≈3.94>3.841,··············
······························································4分所以有95%的把握认为8点前到单位与路线选择有关.············
··························6分(2)选择A方案上班,8点前到单位的概率为0.7,选择B方案上班,8点前到单位的概率为0.5.·······································
·········8分当X=3时,则分两种情况:①若周一8点前到单位,则P1=0.7×C24(1-0.5)2×0.52=2180.·····························································10分
②若周一8点前没有到单位,则P2=(1-0.7)×C34(1-0.5)×0.53=680.··························································12分{#{QQABZYAEogCgAIBAARgCEwXKCkOQkACCAagG
BEAEoAABgQNABAA=}#}2DABCEFMNOxyz综上,P(X=3)=P1+P2=2780.···············································
······················13分16.(本小题满分15分)解:(1)因为E,F分别为线段AB,BC中点,所以EF∥AC.······································
···················································2分因为AM→=2MD→,CN→=2ND→,即DMDA=DNDC=13,所以MN∥AC,所以EF∥MN.·························
···········································4分又MN平面MNB,EF平面MNB,所以EF∥平面MNB.·····································································
············6分(2)取AC中点O,连接DO,OE.因为△ACD为正三角形,所以DO⊥AC.因为平面ACD⊥平面ABC,平面ACD∩平面ABC=AC,DO平面ACD,所以DO⊥平面ABC.····
·············································································8分因为O,E分别为AC,AB中点,则OE∥BC.又因为AC⊥BC,所以OE⊥AC.以O为坐标原点,OE,OC,OD所在直线分
别为x,y,z轴建立空间直角坐标系,·······································································································10分则D(0,0,332),B(3,32,
0),M(0,-12,3),N(0,12,3),故→BM=(-3,-2,3),→MN=(0,1,0),→BD=(-3,-32,332).设平面MNB的法向量为n=(x,y,z),直线BD与平面MNB所成角为θ,则n·→BM=0,n·→MN=0,即
-3x-2y+3z=0,y=0.取n=(3,0,3).···················································································12分则s
inθ=|cos<→BD,n>|=|→BD·n||→BD||n|=|-33+0+932|9+94+274×3+9=33232×23=28,所以BD与平面MNB所成角的正弦值为28.················································
··15分{#{QQABZYAEogCgAIBAARgCEwXKCkOQkACCAagGBEAEoAABgQNABAA=}#}317.(本小题满分15分)解:(1)因为an=(-1)n+2n,则a1=1,a2=5,a3=7,a4=17.又bn=an+1-λan,则b1=a2-λa1=5-λ
,b2=a3-λa2=7-5λ,b3=a4-λa3=17-7λ.·····················2分因为{bn}为等比数列,则b22=b1·b3,所以(7-5λ)2=(5-λ)(17-7λ),…………………
4分整理得λ2-λ-2=0,解得λ=-1或2.因为λ>0,故λ=2.当λ=2时,bn=an+1-2an=(-1)n+1+2n+1-2[(-1)n+2n]=(-1)×(-1)n+2n+1-2×(-1)n-2n+1=-3×(-
1)n.·····································6分则bn+1bn=-3×(-1)n+1-3×(-1)n=-1,故{bn}为等比数列,所以λ=2符合题意.·····················································
························7分(2)bn·n2=-3×(-1)n·n2,当n为偶数时,Tn=-3×[-12+22-32+42-52+62-…-(n-1)2+n2]=-3×(1+2+…+n)=-32n(n+1).··················
····································10分当n为奇数时,Tn=Tn+1-bn+1(n+1)2=-32(n+1)(n+2)+3(n+1)2=32n(n+1).·························
······························································12分综上,Tn=32n(n+1),n为奇数,-32n(n+1),n为偶数.因为Ti·Ti+2>0,又Ti·Ti+2=15Ti+1
,故Ti+1>0,所以i为偶数.···································································13分所以[-32i(i+1)]·[-32(i+2
)(i+3)]=15×32(i+1)(i+2),整理得i2+3i-10=0,解得i=2或i=-5(舍),所以i=2.························································································15
分18.(本小题满分17分)解:(1)由题意可知c=6,点T在C上,根据双曲线的定义可知|TF1|-|TF2|=2a,即2a=(36)2+(10)2-(6)2+(10)2=4,所以a=2,·········
··················2分{#{QQABZYAEogCgAIBAARgCEwXKCkOQkACCAagGBEAEoAABgQNABAA=}#}4则b2=c2-a2=2,所以C的方程为x24-y22=1.······
·······························································3分(2)①设B(x0,y0),DB→=(x0-1,y0).因为DA→=3DB→,所以DA→=(
3x0-3,3y0),所以A点坐标为(3x0-2,3y0),···································································5分因为A,B在双曲
线C上,所以x204-y202=1,(3x0-2)24-(3y0)22=1,解得x0=3,y0=±102,·································································
·······7分所以A点坐标为(7,±3102),所以SΔF1F2A=12|yA|×|F1F2|=12×3102×26=315.···································8分
②当直线l与y轴垂直时,此时PQ=4不满足条件.设直线l的方程为x=ty+1,A(x1,y1),B(x2,y2),P(xP,0),Q(xQ,0).直线l与C联立x24-y22=1,x=ty+1,消去x,得(t2-2)y2+2ty-3=0,所以y
1+y2=-2tt2-2,y1y2=-3t2-2.·····················································10分由Δ=4t2+12(t2-2)>0,t2-2≠0
.,得t2>32且t2≠2.以AB为直径的圆方程为(x-x1)(x-x2)+(y-y1)(y-y2)=0,令y=0,可得x2-(x1+x2)x+x1x2+y1y2=0,则xP,xQ为方程的两个根,所以xP+xQ=x1+x2,xPxQ=
x1x2+y1y2,···················································13分所以PQ=|xP-xQ|=(xP+xQ)2-4xPxQ=(x1+x2)2-4(x1x2+y1y2)=(x1-x2)2-4
y1y2=t2(y1-y2)2-4y1y2=t2(y1+y2)2-4(t2+1)y1y2=4t4(t2-2)2+12(t2+1)t2-2=16t4-12t2-24(t2-2)2=2.···············································
············15分解得t2=-2(舍)或t2=53,即t=±153,所以直线l的方程为:3x±15y-3=0.··················································17分{#{QQABZY
AEogCgAIBAARgCEwXKCkOQkACCAagGBEAEoAABgQNABAA=}#}519.(本小题满分17分)解:(1)当a=1时,f(x)=ex-1+x2-3x+1,则f'(x)=ex-1+2x-3,所以曲线y=f(x)在x=1处
切线的斜率k=f'(1)=0.又因为f(1)=0,所以曲线y=f(x)在x=1处切线的方程为y=0.···················································3分
(2)f(1)=e1-a-2a+1,f'(x)=ex-a+2ax-3a,则f'(1)=e1-a-a,当a>1时,f''(x)=ex-a+2a>0,则f'(x)在(1,+∞)上单调递增.因为f'(1)=e1-a-a<e1-1
-1=0,f'(a)=1+2a2-3a=(2a-1)(a-1)>0,所以存在唯一的x0∈(1,a),使得f'(x0)=0.·······················································5分当x∈(1,x0)时,f'(x)<0,所以f(x)在[1,x
0)上单调递减;当x∈(x0,+∞)时,f'(x)>0,所以f(x)在(x0,+∞)上单调递增.又因为f(1)=e1-a-2a+1<e0-2+1=0,所以f(x0)<f(1)<0.又因为f(3)=e3-a+1>0,所以当a>1时,f(x)在[
1,+∞)上有且只有一个零点.···································8分(3)①当a>1时,f(1)=e1-a-2a+1<e0-2+1=0,与当x≥0时,f(x)≥0矛盾,所
以a>1不满足题意.···········································································9分②当a≤1时,f(0)=e-a+1>0,f'(x)=ex-a+2ax-3a,f''(x)=ex-a+2a,f''(
0)=e-a+2a.记函数q(x)=e-x+2x,x≤1,则q'(x)=-e-x+2,当x∈(-ln2,1)时,q'(x)>0,所以q(x)在(-ln2,1)单调递增;当x∈(-∞,-ln2)时,q'(x)<0,所以q(x)在(-∞,-ln2)单调递减,所以q(x)≥q
(-ln2)=2-2ln2>0,所以f''(0)>0.又因为f''(x)在[0,+∞)上单调递增,所以f''(x)≥f''(0)>0,所以f'(x)在[0,+∞)上单调递增.························
········11分(i)若f'(0)=e-a-3a≥0,则f'(x)≥f'(0)≥0,所以f(x)在[0,+∞)上单调递增,则f(x)≥f(0)>0,符合题意;·························································
··········13分(ii)若f'(0)=e-a-3a<0,可得a>0,则0<a≤1.因为f'(1)=e1-a-a≥0,且f'(x)在[0,+∞)上单调递增,{#{QQABZYAEogCgAIBAARgCEwXKCkOQkACCAagGBEAEoAABgQNABAA=}#}6所以存
在唯一的x1∈(0,1],使得f'(x1)=0.当x∈(0,x1)时,f'(x)<0,所以f(x)在(0,x1)上单调递减,当x∈(x1,+∞)时,f'(x)>0,所以f(x)在(x1,+∞)上单调递增,其中x1∈(0,1],且ex1-a+2ax1-3
a=0.························································15分所以f(x)≥f(x1)=ex1-a+ax12-3ax1+1=3a-2ax1+ax12-3ax1+1=ax12-5ax1+3a+1=a(x12-5x1+3)+
1,因为x1∈(0,1],所以x12-5x1+3∈[-1,3).又因为a∈(0,1],所以a(x12-5x1+3)≥-1,所以f(x)≥0,满足题意.结合①②可知,当a≤1时,满足题意.综上,a的取值范围为(-∞,1].···············
··············································17分{#{QQABZYAEogCgAIBAARgCEwXKCkOQkACCAagGBEAEoAABgQNABAA=}#}