满分5 >
高中数学试题 >
在等差数列{an}中,a1=3,a4=2,则a4+a7+…a3n+1等于 .
在等差数列{an}中,a1=3,a4=2,则a4+a7+…a3n+1等于 .
考点分析:
相关试题推荐
定义在 R上的函数y=f(x)是减函数,且函数y=f(x+2)的图象关于点(-2,0)成中心对称,若s,t满足不等式组
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065007_ST/0.png)
,则当2≤s≤3时,2s+t的取值范围是( )
A.[3,4]
B.[3,9]
C.[4,6]
D.[4,9]
查看答案
7、一个几何体的三视图如图所示,则该几何体的体积是( )
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065006_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065006_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065006_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065006_ST/2.png)
D.1
查看答案
已知P(x,y)是中心在原点,焦距为10的双曲线上一点,且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/0.png)
的取值范围为(-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/1.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/2.png)
),则该双曲线方程是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/3.png)
-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/4.png)
=1
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/5.png)
-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/6.png)
=1
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/7.png)
-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/8.png)
=1
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/9.png)
-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065005_ST/10.png)
=1
查看答案
如图:圆O的割线PAB经过圆心O,C是圆上一点,PA=AC=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065004_ST/0.png)
AB,则以下结论不正确的是( )
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025124443628306580/SYS201310251244436283065004_ST/images1.png)
A.CB=CP
B.PC•AC=PA•BC
C.PC是圆O的切线
D.BC
2=BA•BP
查看答案