题目
题型:北京期末题难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193643-78327.gif)
(1) 求m、n的值;
(2)求直线PC的解析式;
(3)请探究以点A为圆心、直径为5的圆与直线 PC的位置关系,并说明理由。
(参考数:
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193643-71647.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193643-14988.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193643-96549.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193644-79889.gif)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193644-64602.gif)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193644-82109.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193644-17759.gif)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193645-97225.gif)
(2)∵
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193645-56813.gif)
∴ P(-1,-2),C
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193645-39419.gif)
设直线PC的解析式是,则
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193645-22920.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193646-87749.gif)
∴ 直线PC的解析式是
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193646-71377.gif)
(3)如图,过点A作AE⊥PC,垂足为E,
设直线PC与轴交于点D,则点D的坐标为(3,0)
在Rt△OCD中,∵ OC=
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193646-46765.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193646-22786.gif)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193647-32075.gif)
∵ OA=3,,∴AD=6
∵ ∠COD=∠AED=90。,∠CDO公用,
∴ △COD∽△AED
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193647-71041.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193647-20371.gif)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193647-57839.gif)
∵
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193648-53141.gif)
∴ 以点A为圆心、直径为5的圆与直线PC相离。
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193648-59249.gif)
核心考点
试题【如图,抛物线交x轴于A、B两点,交y轴于点C,点P是它的顶点,点A的横坐标是-3,点B的横坐标是1。(1) 求m、n的值;(2)求直线PC的解析式;(3)请探究】;主要考察你对二次函数的应用等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193632-76239.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193632-22029.gif)
(1)求二次函数的解析式;
(2)点P为线段BM上的一个动点,过点P作x轴的垂线PQ,垂足为Q,若OQ=m,四边形ACPQ的面积为S,求S关于m的函数解析式,并写出m的取值范围;
(3)探索:线段BM上是否存在点N,使△NMC为等腰三角形;如果存在,求出点N的坐标;如果不存在,请说明理由。
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193633-33477.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193625-88833.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193625-29476.gif)
(2)抛物线的关系式为( ),其顶点坐标为( );
(3)将三角板ABC绕顶点A逆时针方向旋转90°,到达
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193625-19833.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193618-81631.gif)
(2)当0<k≤1时,求S与k之间的关系式;
(3)当k<0时,求S与k之间的关系式,是否存在k的值,使得以P、B、C、D为顶点的多边形为平行四边形,若存在,求此时的值.若不存在,请说明理由;
(4)若规定k=0时,y=m是一条过点(0,m)且平行于x轴的直线.当k≤1时,请在下面给出的直角坐标系中画出S与k之间的函数图象,求S的最小值,并说明此时对应的以P、B、C、D为顶点的多边形的形状。
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020193601-35874.gif)
(2)当t=4秒时,P、Q两点之间的距离是多少?
(3)当t为多少秒时,以点C、P、Q为顶点的三角形与△ABC相似?