已知正方体ABCD-A
1B
1C
1D
1的棱长为2,点E、F分别在底面正方形的边AB、BC上,且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677020_ST/0.png)
,点G为棱A
1B
1的中点.
(1)在图中画出正方体过三点E、F、G的截面,并保留作图痕迹;
(2)(理)求(1)中的截面与底面ABCD所成锐二面角的大小.
(3)(文)求出直线EC
1与底面ABCD所成角的大小.
考点分析:
相关试题推荐
已知z
1=4-4sinθ+i,其中i为虚数单位,θ∈R.
(1)求|z
1|的取值范围;
(2)如果z
1和
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677019_ST/0.png)
互为共轭复数,求θ.
查看答案
本题共有2个小题,每1小题满分6分.已知集合A={x|3x
2+x-2≥0,x∈R},
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677018_ST/0.png)
.
(1)用区间表示集合A、B;
(2)求A∩B.
查看答案
(文)变量x、y满足下列条件:
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677017_ST/0.png)
则使z=3x+2y的值最小的(x,y)是( )
A.(9,2)
B.(6,4)
C.(4.5,3)
D.(3,6)
查看答案
(理)在正方体ABCD-A
1B
1C
1D
1中,点E在A
1C
1上,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677016_ST/0.png)
且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677016_ST/1.png)
,则( )
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677016_ST/images2.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677016_ST/2.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677016_ST/3.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677016_ST/4.png)
D.
查看答案
已知
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/0.png)
,且向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/1.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/2.png)
平行,则下列说法正确的是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/3.png)
,向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/4.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/5.png)
方向相反
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/6.png)
,向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/7.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/8.png)
方向相同
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/9.png)
,向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/10.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/11.png)
方向相反
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/12.png)
,向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/13.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024182848321667756/SYS201310241828483216677015_ST/14.png)
方向相同
查看答案