p{font-size:10.5pt;line-height:150%;margin:0;padding:0;}td{font-size:10.5pt;}(08年潍

08年潍坊市质检) 已知点P为椭圆和双曲线的一个交点,点F1F2分别是椭圆的左、右焦点,则∠F1PF2的余弦值是        .

答案

答案:

 

相关题目

如图是某无机化合物的二聚分子,该分子中A、B两种元素都是
如图是某无机化合物的二聚分子,该分子中A、B两种元素都是第3周期的元素,分子中所有原子的最外层电子数都达到8个电子的稳定结构。下列说法不正
将两个大小不同的含角的直角三角板如图1所示放置在同一平
将两个大小不同的含角的直角三角板如图1所示放置在同一平面内.从图1中抽象出一个几何图形(如图2),、、三点在同一条直线上,连结. 求证:△≌
The girl has ________ great talent for writing. Up to now, she has written six
The girl has ________ great talent for writing. Up to now, she has written six books, including ________ book about the robot. A.a; a                              B.t
阅读下面的文言文,完成小题。 (每小题3分,共9分)①秦
阅读下面的文言文,完成小题。 (每小题3分,共9分)①秦王谓唐雎曰:“寡人以五百里之地易安陵,安陵君不听寡人,何也?且秦灭韩亡魏,而君以
 —I have studied growing plants as one of my interests. Could I make some su
 —I have studied growing plants as one of my interests. Could I make some suggestions? —______. A. You will make it.       B. Go right ahead. C. Don’t mention it.       D. Take i
The USA is a land of immigrants. Between 1815 and 1914, the world witnessed the
The USA is a land of immigrants. Between 1815 and 1914, the world witnessed the greatest peaceful migration in its history: 35 million people, mostly Europeans, left their homelands to start new liv
设ω>0,若函数f(x)=2sinωx在[-,]上单调递增,则ω的取值
设ω>0,若函数f(x)=2sinωx在[-,]上单调递增,则ω的取值范围是_________.
在下面句子中的空格处填上恰当的虚词,最恰当的一项是 ①
在下面句子中的空格处填上恰当的虚词,最恰当的一项是 ①无论春天夏初在麦苗地_______油菜地里追逐红靛儿,还是天高气爽的秋季,奔跑在柳树下面网