题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045502-35956.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045502-38378.png)
(1)若
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045503-20457.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045503-74815.png)
(2)设
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045503-56891.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045504-62436.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045504-28327.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045504-51538.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045504-87362.png)
解析
试题分析:解: (1) 由
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045503-20457.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045505-95954.png)
故
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045505-81280.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045505-97852.png)
(2)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045505-79862.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045504-62436.png)
故
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045506-37979.png)
平方后得:
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045506-74382.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045506-75222.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045506-16543.png)
点评:本题考查向量的相关知识点及三角恒等变换,这两方面知识点的结合是近年命题的热点。
核心考点
试题【已知向量,(1)若,求 (2)设,若,求的值. 】;主要考察你对平面向量数量积的意义等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045456-22298.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045456-11629.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045456-89759.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045456-36943.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045451-64543.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045451-31484.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045452-48436.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045452-57452.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045452-16887.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045446-28414.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045446-60209.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045446-70231.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045446-19953.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045447-56681.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045447-47247.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045447-74639.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045440-22526.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045440-81942.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045440-68443.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045441-17318.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045441-27465.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045441-53327.png)
A.![]() | B.![]() | C.![]() | D.![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045434-61171.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045434-42827.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045434-68003.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045434-68003.png)
(Ⅰ)若
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045435-15593.png)
(Ⅱ)求
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104045435-26453.png)
最新试题
- 1血液中的血红蛋白和肌肉中的肌动蛋白结构不同的原因是[ ]A.所含氨基酸的种类不同 B.所含氨基酸的数目不同 C.
- 2下列从左到右的变形属于因式分解的是()A.x2–2xy+y2=x(x-2y)+y2B.x2-16y2=(x+8y)(x-
- 3昆虫的身体分为_______、_______、_________三部分。
- 4在下图中所示的四种情景中,人对物体做功的是[ ]A.B.C.D.
- 5已知△ABC的三边长分别是6,8,10,则△ABC外接圆的直径是______.
- 6如果角的终边经过点,则A.B.C.D.
- 7庄子在《骈拇》中写道:“自三代以下者,天下莫不以物易其性矣。小人则以身殉利,士则以身殉名,大夫则以身殉家,圣人则以身殉天
- 8按要求写出化学方程式(1)细铁丝在氧气中燃烧:______(2)实验室用高锰酸钾制取氧气:______(3)实验室制取二
- 9– How time management can be _____ to your corporation?– Thi
- 10阅读下面的文言文,完成下列各题。刘知俊,字希贤,徐州沛县人也。姿貌雄杰,倜傥有大志。始事徐帅时溥,为列校,溥甚器之,后以
热门考点
- 1根据句意和首字母提示填空。1. The Spring Festival is often in F______. 2.
- 2如果3x+12的立方根是3,求2x+6的平方根.
- 3已知三棱锥S-ABC的侧棱和底面边长均为a,SO⊥底面ABC,垂足为O,则SO= (用a表示).
- 4小亮经血液检查,发现他的红细胞个数偏少。小亮可能得的病症是( )A.贫血B.遗传病C.扁桃体发炎D.缺钙
- 5The Human Genome(基因组) Project, a great $3 billion, 15-year t
- 6科学家通过对鼠和人控制抗体产生的基因进行拼接,实现了对鼠源杂交瘤抗体的改造,生产出对人体的不良反应减少、效果更好的鼠—人
- 7下列加线成语的使用,正确的一项是( )(2分)A.真正的朋友应该是心有灵犀的,应该是淡泊名利的。伯牙、子期,庄周、
- 8When the old man ______ to walk back to his house, the sun
- 9我国保护未成年人的两部专门法律是( )①《中华人民共和国婚姻法》 ②《中华人民共和国预防未成年人犯罪法》③《中学生
- 10下列说法正确的是A.用加温或加压的方法不能改变原子核衰变的半衰期B.某原子核经过一次衰变后,核内质子数减少4个C.射线是