如图所示,已知多面体
的底面
是边长为2的菱形,
底面
,
且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/20/22ff1c1c-c66e-4232-b1ae-07b755a9820b.png?resizew=185)
(1)证明:
平面
;
(2)若
,求异面直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9bf53e97203aa720fe3a09b9bf534af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eb4e39d65a8faaf9092fc689adb7582.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8e0f24301cd1bfb1348f4d51f5d4d4a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/20/22ff1c1c-c66e-4232-b1ae-07b755a9820b.png?resizew=185)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/932a04304f2d4975955d4baabb2deeea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4d781525777c7b5284dffc70b2a28a.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05740f0c6071846227dc0ec177ad15e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
更新时间:2020-06-10 23:36:00
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】如图所示,在长方体
中,
,
,
,
为棱
上一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/4eafea3d-9642-4f2a-b69d-48b8ad619fe3.png?resizew=156)
(1)若
,求异面直线
和
所成角的正切值;
(2)若
.试证明:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11337f07e6bc14df4ee625eacf531f43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/4eafea3d-9642-4f2a-b69d-48b8ad619fe3.png?resizew=156)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cc6dd01d471f11d79b26aaa6ffe7415.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9399c9a2a31b0e3165aea2d6ccc4f7c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f66fb71b75b63594ebeeeebd1963eed5.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb514bc9eeabe59f4f585aebf50f2443.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7767d492158189b23af332a8016ed37d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adfc67f86e81cdd466230531ac658016.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,SD垂直于正方形ABCD所在的平面,AB=1,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4d51be6693288c423b4bdd106e3ef5d.png)
![](https://img.xkw.com/dksih/QBM/2011/5/12/1570192810598400/1570192815865856/STEM/8a08481478814f158bd936a7cfc32c21.png?resizew=135)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1197dd6b99f28faac2cade24b7d52229.png)
(2)设棱SA的中点为M,求异面直线DM与SC所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4d51be6693288c423b4bdd106e3ef5d.png)
![](https://img.xkw.com/dksih/QBM/2011/5/12/1570192810598400/1570192815865856/STEM/8a08481478814f158bd936a7cfc32c21.png?resizew=135)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1197dd6b99f28faac2cade24b7d52229.png)
(2)设棱SA的中点为M,求异面直线DM与SC所成角的大小.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,正三棱柱
中,
,
,N为AB的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/1/2443417d-3174-4e6d-8e74-411010cc7c3c.png?resizew=209)
(1)求证:
平面
;
(2)求A到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ef8866ccf160ddc441bf69c5d3a3d5a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/1/2443417d-3174-4e6d-8e74-411010cc7c3c.png?resizew=209)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89006cac018a9875f65ed7bd429c61bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9593b5bde2cef14d5ca46973420f62b.png)
(2)求A到平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9593b5bde2cef14d5ca46973420f62b.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,四棱锥
中,
底面
,
,
,
为
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/5e52897b-2164-491b-a5ed-6f4e06aa76ce.png?resizew=194)
(1)求证:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bce559fceb4731f8d4323410075a22b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5432563bcd56d87f227b72cc253a8e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/710a817143cb1bccd5437000c2577167.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/5e52897b-2164-491b-a5ed-6f4e06aa76ce.png?resizew=194)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4be8d283c93a92689a5f560d9d93f340.png)
您最近一年使用:0次