题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014117-18689.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014117-50550.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014117-87940.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014118-57209.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014118-33465.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014118-29687.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-91379.png)
(1)求点P的轨迹方程;
(2)是否存在定直线
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-58277.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-58277.png)
答案
(2)存在定直线x=
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-42995.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-42995.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-23798.png)
解析
试题分析:(1)设B(0,t),设Q(m,0),t2=
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-86438.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-36133.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-89474.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-51249.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-55512.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-86438.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-20052.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-86438.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-90985.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014122-31421.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-36133.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-55512.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-20052.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-90985.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-51249.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-86438.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-86438.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014122-31421.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-51249.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-51249.png)
(2)由(1),点P的轨迹方程是y2=x;设P(y2,y),
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014120-36133.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014122-58627.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014122-71748.png)
L=2
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014122-41897.png)
=2
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014123-77795.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014123-76582.png)
若a为常数,则对于任意实数y,L为定值的条件是a-
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-42995.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-42995.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-23798.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014121-51249.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-42995.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-42995.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014119-23798.png)
点评:中档题,首先利用几何条件,确定向量的坐标,并运用向量的坐标运算,确定得到抛物线方程。在直线与圆的去位置关系研究中,充分利用了圆的“特征三角形”,确定弦长。
核心考点
试题【已知,点B是轴上的动点,过B作AB的垂线交轴于点Q,若,.(1)求点P的轨迹方程;(2)是否存在定直线,以PM为直径的圆与直线的相交弦长为定值,若存在,求出定直】;主要考察你对平面向量的基本定理及坐标表示等知识点的理解。[详细]
举一反三
A.直角坐标平面内直线的倾斜角的取值范围是![]() |
B.直角坐标平面内两条直线夹角的取值范围是![]() |
C.平面内两个非零向量的夹角的取值范围是![]() |
D.空间两条直线所成角的取值范围是![]() |
A.![]() | B.![]() |
C.![]() | D.![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014100-12593.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014100-79975.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014101-86891.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014101-63541.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014101-54738.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014055-58492.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014056-69628.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014056-88094.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014056-91865.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014056-20675.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014051-27399.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014051-30503.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104014051-46522.png)
最新试题
- 1一个质量为4千克、初速度为2米/秒的物体,从t=0的时刻受到力F的作用,力F跟时间的关系如图所示,若开始的时刻力F的方向
- 2下列药品中,不需要密闭保存的是( )A.食盐B.浓硫酸C.烧碱D.浓盐酸
- 32008年2月18日春季学期开学,扬州市城乡义务教育阶段42.3万名学生免费领取课本。扬州市免费提供城乡义务教育阶段学生
- 4仿照下面的句子,运用比喻的修辞手法,写一句话。 江南是一局棋,纵横交错的田垄是棋盘,星星点点的湖泊是棋子。答:__
- 5某宾馆有客房90间,当每间客房的定价为每天140元时,客房会全部住满.经调查发现,每间客房每天的定价每涨10元,就会有5
- 6下列观点,体现了明末清初儒家思想的新发展的是 [ ]A.“天下为主,君为客” B.“心外无物,心外无理” C.
- 7The doctor_______the patient with great care and said there
- 8使成都平原变得“水旱从人,不知饥馑”的水利工程的是[ ]A.都江堰B.灵渠C.隋朝大运河D.元朝大运河
- 9中国特殊的国情决定了农业、农民、农村问题在中国的极端重要性。新中国成立以来,农村经济经过了曲折发展的历程。当前,中国新的
- 101851年,英国举办世界博览会,在展览会的入口处,摆放了一块重达24吨的大煤块,其主要目的是( )A.宣布英国工业革命
热门考点
- 1Tiger Woods said that he needed to have his attention _____
- 2已知:如图,在△ABC中,中线BE,CD交于点O,F,G分别是OB,OC的中点.求证:四边形DFGE是平行四边形.
- 3李洋同学在实验室用木炭和氧化铜两种黑色粉末在高温下反应制取单质铜,反应的化学方程式为:C+2CuO2Cu+CO2↑ 他联
- 4若样本1+x1,1+x2,1+x3,…,1+xn的平均数是10,方差为2,则对样本2+x1,2+x2,2+x3,…,2+
- 5阅读下面的这首唐诗,然后回答问题。裴迪书斋望月钱 起夜来诗酒兴,月满谢公楼①。影闭重门静,寒生独树秋。鹊惊随叶散,萤远入
- 6下列说法体现基督教人文主义精神的是( )①因行称义学说 ②因信称义学说 ③先定论 ④允许神职人员结婚A.①②③B.
- 7将下列主动语态变成被动语态。1. We must finish the work in two days. The
- 8下列各组词语中,加粗字的注音全部正确的一组是[ ]A.彳亍(chù) B.箕(qí)踞 C.戮(lù)力 D
- 9方程|2009x-2009|=2009的解是( )。
- 10【题文】已知函数是奇函数,则函数的定义域为