您所在的当前位置：高中数学试题 >

平面向量数量积的意义

> 12分）已知向量 a= ， b= ，且 a ,b 满足关系｜ ka+ b｜= ｜ a- kb｜( k＞0). 探究： a能否和 b垂直？ a能否和 b平行？若不能，说明理由；若能，求出相应的 k值. .

问题：

发布时间：2024-09-07

12分）已知向量 a= ， b= ，且 a ,b
满足关系｜ ka+ b｜= ｜ a- kb｜( k＞0).
探究： a能否和 b垂直？ a能否和 b平行？若不能，说明理由；若能，求出相应的 k值.
.

参考答案：

提问用户：0b***6fh

可能感兴趣的题目：

1 完形填空。 I saw the old man, with his untidy clothes and messy hair, as he dashed between the rows of the department store. He was trying to be ordinary but he was hard not to 1 . He 2 the saleswoman and with a slight 3_, possibly German, asked where the women"s shoes were sold. "Fourth floor." She responded in a voice I could hear 10 miles away. "Pardon? Where did you say they were?" he asked again, apparently 4_. Clearly the old man was somewhat 5 "Fourth floor, sir," the friendly saleswoman replied patiently, this time so _6_ that customers turned to see what was causing the _7 . I continued watching as the man thanked the saleswoman and 8 for what I assumed was the fourth floor. But rather than walk to the 9 or the lift, he dashed behind a shelf, took out a notebook and started writing hurriedly, with an almost mad 10 on his face. Then he went straight up to another saleswoman and asked where the women"s shoes were sold. Again he asked her to 11 the answer and once more he walked away and took down some notes. He did this three more times before a department store 12 , thinking him mad, removed him from the store. But rather than be 13 , the old man departed with a huge smile on his face. Although the incident was 1 4 , it was not until a year later, during my first year of university, that I gave it any further 15_. I walked into my language classroom and met my professor. It was that very same man. ( )1. A. see ( )2. A. followed ( )3. A. doubt ( )4. A. confused ( )5. A. silly ( )6. A. angrily ( )7. A. disturbance ( )8. A. put away ( )9. A. shoes ( )10. A. confusion ( )11. A. reply ( )12. A.security-guard ( )13. A. arrested ( )14. A. unusua ( )15. A. wonder B. notice B. interviewed B. voice B. amused B. shy B. loudly B. accident B. passed away B. stairs B. appearance B. recite B. customer B. embarrassed B. serious B. sense C. neglect C. chose C. accent C. annoyed C. deaf C. suddenly C. pleasure C. pulled away C. exit C. pain C. repeat C. saleswoman C. relaxed C. dangerous C. thought D. find D. approached D. smile D. tired D. weak D. quickly D. quarrel D. headed off D. sign D. expression D. retell D. policeman D. refused D. unforgettable D. idea
2 it is to swim with your friends in summer! A. What a great fun B. What great fun C. How great fun D. How a great fun
3 求值sin480°=______．
4 如图所示的各图象，用来表示同一种运动规律的是 A.甲、丙 B.甲、丁 C.乙、丙 D.乙、丁
5 读材料回答下列问题。材料一　2011年春节期间，为满足乌鲁木齐市场的需求，大批的新鲜蔬菜瓜果从海南运往新疆。材料二新疆和田地区保护绿洲的三道防线示意图 (1)海南岛和新疆发展农业生产的气候优势分别为(　　) A光照水源 B．热量　光照 C．降水　热量 D．热量　水源 (2)受地理位置、地形、资源等因素的影响，两省区的主要交通方式除了公路、铁路和航空运输外，海南还有________________，新疆还有________________。 (3)新疆和田地区河流补给水源来自_________；海南的河流补给水源来自 _____ ； (4) 三道防线中，林带的作用是________________________；由于林带的保护，绿洲地区的风速比沙丘地区________，气温日较差比沙丘地区________。
6 下列各组离子能够大量共存的是（　　） A．Fe2+、OH-、NO3-、Cl- B．Ag+、H+、Cl-、HCO3- C．Mg2+、Al3+、Cl-、SO42- D．Na+、Ca2+、NO3-、CO32-
7 It is in the school ______ he studied ten years ago ______ he gave a wonderful speech. A．that; where B．where; that C．where; where D．that; that
8 设α是任意角，请直接用任意角的三角函数定义证明：tanα（tanα+cotα）=sec 2α．
9 列车在竖直降落的大雨中匀速直线前进，雨滴在列车侧面的玻璃上会留下轨迹．现在有A、B、C、D四副雨滴的轨迹图，如图所示，其中哪幅轨迹图是正确的 A. B. C. D.
10 将多项式ax 2-4ay 2分解因式所得结果为 A.a（x2-4y2） B.（ax+2y）（ax-2y） C.a（x+4y）（x-4y） D.a（x+2y）（x-2y）