17-18高一·全国·课后作业
1 . 如图,在长方体ABCD-A1B1C1D1中,E是BC上一点,M,N分别是AE,CD1的中点,AD=AA1=a,AB=2a,求证:MN∥平面ADD1A1.
![](https://img.xkw.com/dksih/QBM/2018/11/8/2070969054011392/2076017732132865/STEM/30c860ad5c1946368667df8e0bde1ddb.png?resizew=106)
您最近一年使用:0次
名校
解题方法
2 . 在直三棱柱
中,
,延长
到
,使
,连结
,得到多面体
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/18/c0649f53-6fe9-4239-8690-7a9b86cb856b.png?resizew=240)
(1)证明:
平面
;
(2)若
,
,求多面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2ddd49625097d0a78df7170be4f882e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa265e6bf764ba99120bf8858fc29cc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78b1dd0fbfc62602b496a1ddce721d94.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/18/c0649f53-6fe9-4239-8690-7a9b86cb856b.png?resizew=240)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/504a36c231b8e80724d01649e7c0944f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee3d1518e197f7f25c341da6b1e3483.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58899f5c3638f1e32274137723f99836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92105835f8075cb75dff244e908370b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78b1dd0fbfc62602b496a1ddce721d94.png)
您最近一年使用:0次
2017-06-18更新
|
726次组卷
|
2卷引用:江西省南昌市第十中学2022-2023学年高二上学期期中数学试题