名校
解题方法
1 . 材料: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.运用上述材料解决如下问题:
如图,已知抛物线
的图象与
轴交于
两点,且过点
,
的解析式和点A的坐标;
(2)若将抛物线
的图象向左平移2个单位,再向上平移1个单位得抛物线
的图象.
①设
为抛物线
位于第一象限内图象上的任意一点,
轴于点
,求
的最小值;
②若过抛物线
的焦点
作直线
,与抛物线
交于
两点,再过
两点分别作抛物线的切线,两条切线交于点
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fa0e961df94bc4cc1c8407ed65f2557.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a415f2567685ccf84257ac443f779a5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/423f5e7781b94f96ff4aac23cba2964d.png)
如图,已知抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f61d802cc79e61fc37a79d4bae4e98c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9cda46e575acf64941ea0964b89ee99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/980240503eeea96e431bb5540ba60879.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若将抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4c8a9c4957431681ddfc77895a88508.png)
①设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4c8a9c4957431681ddfc77895a88508.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52cbeb9b1c1d637b903cf3e5c7f730f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f25f0610430d94cc16ca340e3ac5757.png)
②若过抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4c8a9c4957431681ddfc77895a88508.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4c8a9c4957431681ddfc77895a88508.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44091f07aab1b00f3c5abb14d98fed25.png)
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