1 . 已知复数
、
在复平面上对应的点分别为A、B,且
,
,O为坐标原点,则△OAB的周长为___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4856e1b892a7d5aa5bfe3a333b7fdda0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c5be24c4350ad936eddeb4cdbbc67b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5bf3489a641258285319256dc409ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/306912718fde598aedb791bf4390700d.png)
您最近一年使用:0次
2 . 已知椭圆C:
的离心率为
,
、
分别为椭圆C的左、右顶点,
、
分别为椭圆C的左、右焦点,B为椭圆C的上顶点,且
的外接圆半径为
.
(1)求椭圆C的方程;
(2)设与x不垂直的直线l交椭圆C于P、Q两点(P、Q在x轴的两侧),记直线
、
、
、
的斜率分别为
、
、
、
.已知
,求
面积的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad7451b947d1adea22bc04070efdd2b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cfa1e7ffae662aefb49a44c52d4954d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9721059d158853671eaf19e39769b13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd8db4b168ddbcba90ac9b31d36a0432.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e82fe25db889399bb3ca4ffd5dd5db84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a61d572ecf27dc02fcbd588f24647b1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/130c1bb7866e816804248f5eb8c59417.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c68316a6c48b33c53e2725274c8e1d65.png)
(1)求椭圆C的方程;
(2)设与x不垂直的直线l交椭圆C于P、Q两点(P、Q在x轴的两侧),记直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee1d228a6558961e7346d0326207dacf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c69286a11bc6a2641c73542167ce2c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9cfdaad60640c4c023a339ffdc459d7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95dfc574d8ed4f6e828a9c5c40788d02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2562424a83aae7e4b3f8adf90307961a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03b58edb637c5dfa03794f3952de9d83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be76756ea33cd487013256cbe942a3cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9fa1f26b7d3a7a600ad370cfa176f39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7ee33f0fa8b278c793a691206b1fb83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05470dc94e4d9eea98d2c533ce576b07.png)
您最近一年使用:0次
3 . 如果对任意的整数x,y,不等式
恒成立,求最大常数k.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3c0252c0000385c3f7bfb989f266c87.png)
您最近一年使用:0次
4 . 已知函数
在区间
上恒正,则实数a的取值范围为___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a2f9503336c3bf788cdc5e3c91ffdcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae976d6c9c48eb578f1e37394c6709c6.png)
您最近一年使用:0次
5 . 从1,2,3,…,11这11个正整数中任意抽取3个不同的正整数a,b,c,则它们的积abc能被4整除的概率为___________ .
您最近一年使用:0次