娃哈哈z553
幼苗
共回答了12个问题采纳率:83.3% 举报
![](https://img.yulucn.com/upload/7/51/7517d5f935fe9bad9fd0ade69976f573_thumb.jpg)
,
(1)抛物线
![](https://img.yulucn.com/upload/c/bf/cbf3774d891b380b24188171e52a20a3_thumb.jpg)
的焦点为
![](https://img.yulucn.com/upload/d/c3/dc3ea651c6f745208cb8d1dd4a9f62f5_thumb.jpg)
,----------------------------------3分
代入直线
![](https://img.yulucn.com/upload/a/6a/a6a7ebd966ae1d1e7c71b87968918a61_thumb.jpg)
,得
(或用焦点坐标为(0,2)来解)抛物线方程
![](https://img.yulucn.com/upload/7/51/7517d5f935fe9bad9fd0ade69976f573_thumb.jpg)
---------------------7分
(2)设切点坐标为
![](https://img.yulucn.com/upload/9/8a/98a0e976664150f1d12ccc99c80e6828_thumb.jpg)
,----------------------------------------------------------9分
由
![](https://img.yulucn.com/upload/a/74/a74f1a2c4c8019b82cee91b792ef09d5_thumb.jpg)
,得
![](https://img.yulucn.com/upload/9/76/97685fa9c8907151cbc2cca47be92e97_thumb.jpg)
,即
![](https://img.yulucn.com/upload/9/1f/91f590f97fa7ff168f0707cbdfe2f4a4_thumb.jpg)
,--------------------------------------12分
得
![](https://img.yulucn.com/upload/d/ca/dca607533a90d9c6b202e4b21f2a9507_thumb.jpg)
,代入抛物线方程得
切点坐标为
![](https://img.yulucn.com/upload/3/0c/30c10dc58d3cf402b1edd59fe6567d0e_thumb.jpg)
---------------------------------------------------------------15分
1年前
1