1、 1 2015-2016 I 1 0 3 3 y x A 6 B 3 C 3 2 D 6 5 2 an 7 S7=21 a2= 1 a6= A 5 B 6 C 7 D 8 3 a b A b C b b a 4 cos 2 A B C D 5 1 1 1 1 1 OABC 2 1 1 1 1 6, 2 OA OC A 64 B 96 48 2 C 128 D 96 6 1 0 x 2y 2=0 A x 2y 1=0 B x 2y+1=0 C 2x+y 2=0 D x+2y 1=0 2 7 P ABC PA ABC , 1, 3 AC BC AC BC PA A 5 B 2 C 20 D 4 8
2、 ABCD F E, BD AC, AB EF EF CD A 90 B 45 C 60 D 30 9 , xy 20 2 5 0 20 xy xy y 1 1 y z x A 1 ,2 3B 11 , 22 C 13 , 22D 35 , 2210 a b a b A c a b B c a b C c a b D c a b 11 2x+my 1=0 3x 2y+n=0 2 p p m n A 6 B 6 C 4 D 10 12 x y z=2x+y 3 b= A B C 3 D 5 II 3 13 14 2 1 3a+b 15 x y z= x+y 16 (1,2) ( 1,3) 10
3、x ay a _. 17 10 (4,0) A (6,7) B (0,3) C BC BC 18 12 ! 3x+4y 7=0 24 l 19 12 ABC A1B1C1 AA 1C1C AA1C1 AA1B1B AB=4AA1=4 1 D AB AC1 CDB1 4 DA1 AA1C1C 20 12 P ABCD ABCD ABCD AB=2 PD= O AC BD E PB E PBD EAC P EAD 21 12 ) ( 1 ) 1 ( : 1 R k x k y l . 1 l 1 l 0 2 ) 2 ( 3 : 2 y k x l k . 22 12 an a1=1 a4=7 an
4、+2 2an+1+an=0 n N 1 an 2 bn= n N + bn n Sn DCDBD AADCA CB 5 13 14 15 16 2 (0, ) 317 BC 3 2 0 6 3 7 BC k BC BC 1 BC 2 3 BC A 4 0 BC ) 4 ( 2 3 0 x y 0 12 2 3 y x BC M M 3,5 BC AM 0 20 5 y x 18 l 3x+4y+m=0 x=0 y= y=0 x= 24 =24 l 19 1 A1C AC1 F B1C E DE EF AA1C1C A1C 1B1 EF= A1B1 ABB1A1 D AB 1B1 AD= A1B
5、1 ADEF AC1 CDB1 AC1 CDB1 1 CDB1 2 =4AA1=4 D AB 1=1 AD=2 1 1D= = AA1 2 +A1D 2 =AD 2 1 1 AA1C1 AA1B1B AA1C1 AA1B1B=AA1 1 AC AA1C1C AA1B1B 1D AA1B1B 1D 1 AA1C1C AC AA1C1C 1=A 1 AA1C1C 20 ABCD AC ABCD ABCD PBD 6 AC EAC PBD EAC PBD=OE BD PB AD H BH ABCD PAD = = 21 1 ) ( 1 ) 1 ( : 1 R k x k y l 1 ( 1) y k x ) 1 , 1 ( 2 12 kk k k 2 3 1 k 3 k 1 k 1 : 2 0 l y x 2 2 :0 3 l x y 2 2 22 3 3 2 d 22 1 n+2 2an+1+an=0 n N n+2 an+1=an+1 an n N an 1=1 a4=7 d= = =2 n=1+2 n 1 =2n 1 2 n=2n 1 n= = = = n= 1 + = 1
