2017届高三数学一轮总复习第五章平面向量与复数第三节平面向量的数量积与平面向量课时跟踪检测文.doc

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2、 |a| 2 |b| 1 a b _ (2a b a b) 6 2a 2 a b b 2 6 |a| 2 |b| 1 a b 1 cos a b a b |a b| 1 2 a b 3 . 35 a 0 a b b a a 2 |a| 2 (a b c a b c) |a b a b. _ (a b c c a b c) a a b |a b a b 3 1 ) a ( 3 1) b (0,1) c (k 3) a 2b c k _. 2 a 2b c (a 2b c 0 a c 2b c 0 3k 3 2 3 0 k 3. 3 2 ) |a| 1 |b| 6 a b a) 2 a b _ a

3、 b a) a b a 2 2 a b 3 cos a b a b |a|b| 3 1 2 a b 3 . 33 ) ABCD AB CD 0 (AB AD AC 0 ABCD _ AB CD 0 AB CD DC ABCD (AB AD AC DB AC 0 ABCD 4 ) ABCD AB 2 AD 1 A M AB AM 1 3 AB DM DB _ DM DA AM AM DA 1 3 AB DB DA AB DM DB DA 1 3AB DA AB) |DA| 2 1 3 |AB| 2 4 3 DA AB 1 4 3 4 3 AD AB 7 3 4 3 |AD AB 7 3 4 3

4、1 2 1. 1 5 ) ABCD AB CD AD AB B AB 2CD 2 M BC MA MD _. 3 MA MD 1 2CB BA 1 2CB CD 1 4 |CB | 2 1 2 CB CD 1 2 CB BA BA CD 1 4 2) 2 1 2 2 1 2 2 1 2 1 2 1 2 2. 2 6 a (2,4) b (1 2) c a (a b)b |c| _. a b 2) 6 c a (a b)b a 6b (2,4) 6(1 2) (8 8) |c| 8 2 2 8 2. 8 2 ) AOB OA OB 1 AB 4AC OC OB OA) _. |AB| 2 |AC

5、 | 2 4 OC OB OA) (OA AC AB OA AB AC AB 2cos 4 2 4 2 1 2 . 1 28 ABC ACB AC BC 1 CO xCA yCB x y 1. f(m) |CA mCB |(m R) 3 2 |CO| _ CO xCA yCB x y 1 A O B |CO| AB AC BC 1 O AB f(m) |CA mCB | 3 2 A BC 3 2 . AC 1 ACB 4 |CO| 1 2 . 1 29 |a| 4 |b| 8 a b (1) |a b| |4a 2b| (2) k (a 2b) (ka b) a b 1 2 16. (1) |

6、a b| 2 a 2 2a b b 2 16 16) 64 48 |a b| 4 3. |4a 2b| 2 16a 2 16a b 4b 2 16) 768 |4a 2b| 16 3. (2) (a 2b) (ka b) (a 2b ka b) 0 ka 2 (2k 1)a b 2b 2 0 16k 16(2k 1) 0. k 7. k 7 a 2b ka b 10 ) A(4,0) B(t,2) C(6 t) t R O (1) ABC t (2) ABCD |OD| (1) AB (t 4,2) AC (2 t) BC (6 t t 2) A AB AC 0 2(t 4) 2t 0 t 2

7、 B AB BC 0 (t 4)(6 t) 2(t 2) 0 t 2 C AC BC 0 2(6 t) t(t 2) 0 t 2 2. (2) ABCD AD BC D (x y) (x 4 y) (6 t t 2) x 10 t y t 2 D(10 t t 2) |OD| t 2 t 2 2t 2 24t 104 t 6 |OD| 4 2. 5 1 a b a b 0 c |c a b| 1 |c| _ a b |a| |b| 1. a b 0 |a b| 2 |c a b| 2 c 2 2c a b) 2a b a 2 b 2 1 2c a b) c 2 1 c 2 1 2 2|c|co

8、s ( c a b ) c 2 2 |c| c 2 2 2|c| 2 c 2 1. 2 1 2 1 2 O ABC OA 2 BC 2 OB 2 CA 2 OC 2 AB 2 O ABC _( ) OA 2 BC 2 OB 2 CA 2 OA 2 OB 2 CA 2 BC 2 (OA OB OA OB) (CA BC CA BC) BA OA OB) BA CA BC) BA OA OB CA BC) 0 BA OA AC OC ) 0 BA OC 0 BA OC . CA OB CB OA O ABC 3 a (1,2) b ( 3,4) c a ( R) (1) |c| c b (2) c a c a (1) c a (1,2) ( 3,4) (1 3 2 4 ) |c| 2 (1 3 ) 2 (2 4 ) 2 5 10 25 2 25 1 52 4 1 5 |c| c 8 5 6 5. c b 8 5 6 5 3,4) 8 5 3) 6 5 0 b c. 1 5 |c| b c. (2) c a 6 cos a c |a|c| 5 5 5 25 2 10 5 1 5 2 2 1 . c a cos 1 t t 1 cos t t 2 t 1 1 4 t 2 8 t 5 1 t 1 t 1 cos 1 0 c (1,2) 0 c a c a