天气预报 > 其他 > 二次曲线系是什么
二次曲线系是什么
更新时间: 2020-07-15 00:00:00  

二次曲线也称圆锥曲线或圆锥截线,是直圆锥面的两腔被一平面所截而得的曲线。当截面不通过锥面的顶点时,曲线可能是圆、椭圆、双曲线、抛物线。当截面通过锥面的顶点时,曲线退缩成一点、一直线或二相交直线。

关键词: 曲线 什么

二次曲线系是什么相关经验

天气预报

最新推荐

页面:/news/view-2017899/ | 耗时:0.2222 s | 内存:2.11 MB | 查询:4 | 缓存读取:3 写入:0 | 加载文件:25
select * from tbl_Articles WHERE ArticleID=2017899 LIMIT 0,1
select * from tbl_Articles_data WHERE ArticleID=2017899 LIMIT 0,1
select * from tbl_Articles_sphinx where id=2017899 LIMIT 0,1
SELECT ArticleID,Title FROM tbl_Articles WHERE ArticleID IN(1059801,1119464,1094177,1091267,1102388,1070922,1059915,1050439,1070993,1078182,1117906,1894368,1085318,1117299,1125951,1093829,1067803,1057696,1106994,1075977,1067035,1102298,1056858,1077569,1091974,1094393,1054612,1123553,1066812,1093975) ORDER BY field (ArticleID,1059801,1119464,1094177,1091267,1102388,1070922,1059915,1050439,1070993,1078182,1117906,1894368,1085318,1117299,1125951,1093829,1067803,1057696,1106994,1075977,1067035,1102298,1056858,1077569,1091974,1094393,1054612,1123553,1066812,1093975)