平顶山许昌济源2021-2022学年高三第二次质量检测文科数学参考答案一、选择题:本题共12小题,每小题5分,共60分。1.B2.D3.C4.A5.C6.D7.B8.A9.A10.B11.D12.B二、填空题:本题共4小题,每小题5分,共20分。202213.314.2315.16.(0,2)4045三、解答题:共70分。解答应写出文字说明、证明过程或演算步骤。第17-21题为必考题,每个试题考生都必须作答。第22、23题为选考题,考生根据要求作答。17.(12分)解:(1)因为acosCcsinA由正弦定理得sinAcosCsinCsinA(sinA0)cosCsinC,又0<c<,c···········································4分4(2)因为2sin(b+)=c-23cosa4\2sin(b+c)=4-23cosaabc,\2sina=4-23cosa\sina+3cosa=2\2sin(a+)=23\a+=þa=···········································8分326ac由正弦定理可得,则sinasinc1,14csina2a22···········································10分sinc22117s=acsinb=224sin2+23.········································12分abc221218.(12分)解:(1)由折线图中数据及题中给出的参考数据,72可得t4,tit28,···········································(2分)i17tityiy1267i1所以r0.88,·············(4分)727227273tityiyi1i1即y与t的相关系数近似值为0.88[0.75,1],所以相关性很强;·············(5分)7259(2)由yi259,得y37,·································(6分)i177tityiyˆ126i1又b74.5,··································(8分)228titi1aˆybˆt374.5419,所以y关于t的回归方程为y4.5t19;·······························(10分)(3)将2022年对应的t8代入回归方程y4.5t19,得y4.581955,所以预测2022年该市某家庭教育支出将达到家庭总支出的5500,因此当某家庭总支出为10万元时,家庭教育支出约为1055005.5万元.......(12分)19.(12分)解:(1)证明:∵dc面abc,bc平面abc∴dcbc∵ab是圆o的直径∴bcac且dcacc∴bc平面acd...........................................................(3分)2,∵四边形dcbe为平行四边形∴bc de="">03x+3>0x+5>0\x<-5或-1</c<,c···········································4分4(2)因为2sin(b+)=c-23cosa4\2sin(b+c)=4-23cosaabc,\2sina=4-23cosa\sina+3cosa=2\2sin(a+)=23\a+=þa=···········································8分326ac由正弦定理可得,则sinasinc1,14csina2a22···········································10分sinc22117s=acsinb=224sin2+23.········································12分abc221218.(12分)解:(1)由折线图中数据及题中给出的参考数据,72可得t4,tit28,···········································(2分)i17tityiy1267i1所以r0.88,·············(4分)727227273tityiyi1i1即y与t的相关系数近似值为0.88[0.75,1],所以相关性很强;·············(5分)7259(2)由yi259,得y37,·································(6分)i177tityiyˆ126i1又b74.5,··································(8分)228titi1aˆybˆt374.5419,所以y关于t的回归方程为y4.5t19;·······························(10分)(3)将2022年对应的t8代入回归方程y4.5t19,得y4.581955,所以预测2022年该市某家庭教育支出将达到家庭总支出的5500,因此当某家庭总支出为10万元时,家庭教育支出约为1055005.5万元.......(12分)19.(12分)解:(1)证明:∵dc面abc,bc平面abc∴dcbc∵ab是圆o的直径∴bcac且dcacc∴bc平面acd...........................................................(3分)2,∵四边形dcbe为平行四边形∴bc>