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2022年哈三中第二次高考模拟考试数学试卷(理工类)答案一、选择题BDCDBCAABCBC二、填空题13:314:215:20216:8三、解答题17.(Ⅰ))34sin(3)(xxf4分增区间)(3108,3
28Zkkk2分对称轴)(3104Zkkx2分(Ⅱ)32,334x2分值域3,232分18.(Ⅰ)样本平均数为............................
...........2众数为12.................................4(Ⅱ)...............................................................
...........6而81860.,..........................................................................9∴818605.,B~X,∴的数学期望0934818605..XE.............
.........................................................1219.(Ⅰ)法1面EADF⊥面BEFC且DFEFDF⊥面BEFCCE面BEFCCEDF
2又CEBF且BF∩DFFCE⊥面DBF
4法2面EADF⊥面BEFC且AEEF,BEEF,AEBE如图所示,建立以E为坐标原点,EA,EF,EB所在直线为x轴,y轴,z轴的空间直角坐标系
1则E(0,0,0)C(0,2,2)B(0,0,2)D(2,2,0)F(0,2,0)EC=(0,2,2)BD=(2,2,-2)B
F=(0,2,-2)设面DBF的法向量为m,00mBDmBF,则m(0,1,1)3EC∥m,即直线
CE面DBF4(Ⅱ)过B作BHAE交AE于点H由已知可得AEEF,BEEF,AE∩BEEEF⊥面ABE
,且AEB为折成二面角的平面角,即3AEBBH面ABEEFBH,取BF的中点I如图所示,建立以H为坐标原点,HA,HI,HB所在直线为x轴,y轴,z轴建立的空间直角坐标系
5则3B(0,0,)E(-1,0,0)3C(0,2,)D(1,2,0)设Mm(1,,0)3EB=(1,0,)3EC=(1,2,)2EMmm=(2,,0)(0)设面
EMC的法向量为1n,1100nECnEM,则143mnm(,-2,)7设直线BE与面EMC所成角为,则1112sincos2||||EBnEBnEBn,解得1
m9则面EMC的法向量为113n(,-2,),面DEM的法向量为2
0n(,0,1)则1212126cos4||||nnnnnn,11设面
与面EMC所成角为,为锐角,则126coscos4nn,1220.(Ⅰ)31a时,1ln2xxxf,22eef,切线方程:eexey223222..
......................................................3分(Ⅱ)当0a,xf在,,110;当310axf在,,11,330aa;当31a,xf在,,,aa33
110;当31a时,xf在,0.............................7分(III)令03ln2axxxf,ax,x3121。①当3ea时,xf在,e,22221aeefxf,32eae。②当3ea时,
22min213ln363213ln3aaaaaaafxf,182331ea,综上,1823312e,ea........................12分21.(Ⅰ)221,1,2222abebb又,22
a,12:22yxC................................................................................................
.............2分(Ⅱ)(ⅰ)设00,yxP,过P点与椭圆C相切的直线方程为00yxxky222200yxyxxky得0224212000022ykxxkxykxk,0得012
22000220ykyxkx,121kk,AB为圆O的直径,即32AB.........................................................6分(ⅱ)设2211,,,yxNyxM,设
PM:11yxxky,222211yxyxxky0得112111122yxxyxk,PM:2211yyxx,同理PN:2222yyxx,MN的方程2222
2200yxyyxx得04443200220yxxxy,02002134yxxx,202021344yyxx,22040202031222yyyyMN。O到MN的距离202042yxd,2020312yySOMN,令
2221120,,t,ty,223222,ttSOMN........12分22.(Ⅰ)2211:29Cxy........................................................................
..2222:14xCy..........................................................................................4(Ⅱ)设(2cos,sin)Q,圆心1(0,2)C2
13sin4sin8CQ..........................................................................61max2213CQ........................................
..................................................7max221133PQ..............................................................................
............9当2sin3时取“=”.........................................................................................1023.(Ⅰ)由题意得,,当时,不等式化为,解得,;当时,不
等式化为,无解;当时,不等式化为,解得,则不等式的解集为或..........................................................4(Ⅱ),即.∵................................6当且仅当时等号成立,
∴2212nm...............................8∴8222223221212nmnm,即xfnm1222...................................10获得更多资源请
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