满分5 >
高中数学试题 >
已知平面区域D由以A(1,3),B(5,2),C(3,1)为顶点的三角形内部以及...
已知平面区域D由以A(1,3),B(5,2),C(3,1)为顶点的三角形内部以及边界组成.若在区域D上有无穷多个点(x,y)可使目标函数z=x+my取得最小值,则m=( )
A.-2
B.-1
C.1
D.4
考点分析:
相关试题推荐
设椭圆
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192005_ST/0.png)
=1(a>0,b>0)的离心率e=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192005_ST/1.png)
,右焦点F(c,0),方程ax
2+bx-c=0的两个根分别为x
1,x
2,则点P(x
1,x
2)在( )
A.圆x
2+y
2=2内
B.圆x
2+y
2=2上
C.圆x
2+y
2=2外
D.以上三种情况都有可能
查看答案
已知点P是双曲线
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192004_ST/0.png)
右支上一点,F是该双曲线的右焦点,点M为线段PF的中点,若|OM|=3,则点P到该双曲线右准线的距离为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192004_ST/1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192004_ST/2.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192004_ST/3.png)
D.
查看答案
已知F
1、F
2是椭圆的两个焦点,满足
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192003_ST/0.png)
•
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192003_ST/1.png)
=0的点M总在椭圆内部,则椭圆离心率的取值范围是( )
A.(0,1)
B.(0,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192003_ST/2.png)
]
C.(0,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192003_ST/3.png)
)
D.[
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192003_ST/4.png)
,1)
查看答案
已知双曲线
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192002_ST/0.png)
的右焦点为F,若过点F的直线与双曲线的右支有且只有一个交点,则此直线斜率的取值范围是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192002_ST/1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192002_ST/2.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192002_ST/3.png)
D.
查看答案
设椭圆
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192001_ST/0.png)
(m>0,n>0)的右焦点与抛物线y
2=8x的焦点相同,离心率为
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192001_ST/1.png)
,则此椭圆的方程为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192001_ST/2.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192001_ST/3.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225209481119248/SYS201311012252094811192001_ST/4.png)
D.
查看答案