芜湖市2018—2019学年度第二学期高三模拟考试数学(文科)参考答案一、选择题(本题共12小题,每小题5分,共60分)题号123456789101112答案BDDBBCDCDADB二、填空题(本题共4小题,每小题5分,共20分)1312;14x-y=0;1564-8π3;167三、解答题(本大题共6小题,共70分解答应写出文字说明、证明过程或演算步骤)17(1)由题意得:a24=a2·a8S8{=72(a1+3d)2=(a1+d)(a1+7d)8a1+28d{=72,解得:a1=d=2,∴an=2n5分……………………………………………………………(2)由(1)得Sn=n2+n,∴bn=1Sn+n=1n2+2n=12(1n-1n+2)7分………………………∴Tn=12[(11-13)+(12-14)+(13-15)+…+(1n-1-1n+1)+(1n-1n+2)]=12(1+12-1n+1-1n+2)=34-12(1n+1+1n+2)<3412分………………………18(1)取A1B1中点为P,连结FP,AP. E,F,P为AC,B1C1,A1B1的中点,∴FP∥AE,FP=AE.∴四边形FPAE为平行四边形,∴EF∥AP.又 AP平面ABB1A1EF平面ABB1A1∴EF∥平面ABB1A15分………………(2)连A1E,BE AB=BC,且E为中点,∴BE⊥AC.又 AC⊥A1B且BE∩A1B=B,∴AC⊥平面A1BE.∴A1E⊥AC.7分……………∴AA1=A1C.又 四边形ACC1A1为菱形,∴AC=AA1=A1C槡=2且A1E⊥AC. 侧面ACC1A1⊥底面ABC,∴A1E⊥底面ABC.由(1)知EF∥平面ABB1A1.∴VF-ABA1=VE-ABA1=VA1-ABE=13·A1E·S△ABE=13×槡62×14=槡62412分………………)页