题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095349-81043.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095349-92759.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095349-48527.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095350-51644.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095350-35659.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095350-25037.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095350-22878.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095350-59701.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095350-16630.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095351-91929.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095351-33761.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095351-35836.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095351-75977.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095352-69911.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095352-90036.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095352-17932.jpg)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095352-39070.png)
解析
试题分析:设
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095349-92759.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095353-76254.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095353-21473.png)
由向量的中点公式可得
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095353-56202.png)
同理可得
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095354-63793.png)
故
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095354-91469.png)
核心考点
举一反三
A.![]() | B.![]() | C.![]() | D.![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095338-17144.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095338-72838.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095331-91983.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095331-71903.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095332-76345.png)
A.1 | B.![]() | C.![]() | D.2 |
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095324-54270.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095324-73551.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095324-64290.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095325-16914.png)
A.![]() | B.![]() | C.![]() | D.1 |
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095316-45323.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095316-17838.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095316-29890.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095316-55814.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095317-42292.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191103/20191103095317-89305.png)
A.![]() | B.![]() | C.![]() | D.![]() |
最新试题
- 1完成表格,比较南地区极与北极地区的不同点.地区南北半球主要矿产资源代表动物有无常住人口海陆分布南极___________
- 2Jack’s sister has been a tour guide _______two years ago.A.f
- 325℃时,将稀氨水逐滴加入到稀硫酸中,当溶液的PH=7时,下列关系正确的是[ ]A.c(NH4+)==c(SO4
- 4四边形ABCD为直角梯形,CD∥AB,CB⊥AB且CD=BC=12AB,若直线L⊥AB,直线L截这个梯形所得的位于此直线
- 52011年是大陆赠台大熊猫“团团”“圆圆”抵台的第三年,2月19日,中国野生动物保护协会名誉会长贾治邦专程来到台北市立动
- 6小明在匀速且沿直线前进的火车车厢里用手竖直向上抛出一玻璃小球,小球将下落到:(忽略空气阻力)[ ]A.小明的前方
- 790载艰苦卓绝,90载荣耀辉煌,90年来,中国共产党带领全国各族人民战胜各种艰难险阻,取得了社会主义革命、建设和改革的伟
- 8一年有两次太阳直射的地方是[ ]A、23.5°S B、赤道 C、66.5°N 或66.5°S D、23.5°N
- 91940年5月,延安各界公奠一位抗战时为国捐躯将军,“一战淝水,再战临沂,三战徐州,四战随枣,鞠躬尽瘁,卒以身殉,全国人
- 102008年5月12日在我省坟川发生了里氏8.0级特大地震,在众志成城、举国抗震救灾的日子里,为了尽快让全国人民了解震中汉
热门考点
- 1中学生小李从某商场买回一辆自行车,第二天当他骑这辆车上学时,自行车横梁突然断裂,致使他被摔成重伤。在与该商场协商赔偿无果
- 2请认真阅读下面诗文,完成下列各题。苏世长讽谏武德四年,王世充平后,其行台仆射苏世长,以汉南归顺。高祖责其后服,世长稽首曰
- 3过科学家的不懈努力,找到了获取核能的两条途径:_________ 和_________。
- 4阅读下面一段文字,按要求作文。(来源于课本必修三81页)古希腊传说中有一个很凄美的故事。美丽的女教士希洛与对岸阿拜多斯城
- 5All the neighbours admired this family _____ the parents are
- 6在△ABC中,已知(AB|AB|+AC|AC|)⊥BC,且,2AB•AC=|AB|•|AC|则△ABC的形状是 ____
- 7如图所示,在曲轴上悬挂一个弹簧振子,曲轴不动时让其上下振动,振动周期为T1.现使把手以周期T2匀速转动,T2>T1,当其
- 8被太平洋、印度洋和大西洋包围的大洲是[ ]A.北美洲B.南极洲C.非洲D.大洋洲
- 9The children remembered to ______ themselves at first, but t
- 10造成温室效应的气体是( )A.二氧化碳B.二氧化硫C.二氧化氮D.氮气