名校
解题方法
1 . 对抛物线
,定义:点
叫做该抛物线的焦点,直线
叫做该抛物线的准线,且该抛物线上任意一点到焦点的距离与它到准线的距离相等.运用上述材料解决以下问题:
如图,已知抛物线
:
的图象与
轴交于
、
两点,且过点
.
(1)求抛物线
的解析式和点A坐标;
(2)若将抛物线C的图象向左平移4个单位,再向上平移4个单位得到抛物线D的图象.
①设
为抛物线
上任意一点,
轴于点N,求
的最小值;
②直线l过抛物线D的焦点且与抛物线D交于
两点,证明:以
为直径的圆与抛物线D的准线相切.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fa0e961df94bc4cc1c8407ed65f2557.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fd81b3c7a12b2c2623d4336751e3ed5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/423f5e7781b94f96ff4aac23cba2964d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/7/ab0eb186-9b21-435c-8f0d-4c645bfd9955.png?resizew=343)
如图,已知抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6c4cd33c7a1f5d3b5ea44a3e03610c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be4715dd5f2139c84d0302095d226302.png)
(1)求抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若将抛物线C的图象向左平移4个单位,再向上平移4个单位得到抛物线D的图象.
①设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52cbeb9b1c1d637b903cf3e5c7f730f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ed953fccffc4f4d133e7a41472127d7.png)
②直线l过抛物线D的焦点且与抛物线D交于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6bce3d91ca23b86d8c6625f2632e437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
您最近一年使用:0次