在四棱锥
中,
平面
,且底面
为边长为2的菱形,
,
.
(1)记
在平面
内的射影为
(即
平面
),试用作图的方法找出M点位置,并写出
的长(要求写出作图过程,并保留作图痕迹,不需证明过程和计算过程);
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/30/4d27cde3-f8e6-4443-85a2-eb3bd7168a7b.png?resizew=191)
(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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71a46dc0bb5d8fa33583817e530a5d21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41cd5c4f8b106d01e0e431078e1a468b.png)
(1)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d0492b25f10ae45c39f8e9838519259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/30/4d27cde3-f8e6-4443-85a2-eb3bd7168a7b.png?resizew=191)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
更新时间:2018-04-29 15:33:09
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图所示,在直四棱柱
中,
,
,点M是棱
上一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/16/20b96fe1-88cb-459b-84d0-40691508d497.png?resizew=168)
(1)求证:
;
(2)试确定点M的位置,使得平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b9e89a70b8b446861ce6f35fa83b251.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70734a8e672376bb0bd1522e229f86a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/16/20b96fe1-88cb-459b-84d0-40691508d497.png?resizew=168)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7711afeb265550ead8321ea2a24d5.png)
(2)试确定点M的位置,使得平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66dbce362af5e40a3db7115067d47955.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c52091eb745de866044477641a7c55f.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】已知梯形
如图(1)所示,其中
,
,
,
,过点A作BC的平行线交线段CD于M,点N为线段BC的中点.现将
沿AM进行翻折,使点D到达点P的位置,且平面
平面
,得到的图形如图(2)所示.
![](https://img.xkw.com/dksih/QBM/2022/1/16/2895941057585152/2896563462602752/STEM/a12e0e12-89e1-457a-b5ad-e92d59649197.png?resizew=468)
(1)求证:
;
(2)若
,若点H为线段PC的中点,求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce0d7095ddd69d6ceaf1065b1bc2c79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/386c7de62e8f9a8161ebaefe6b4ec35e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73e4150583bb730627d98e250153a704.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50244defdb202cc420e1d6a910241c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392469b357b12b998528499929366c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53bdef2e7a7929ad6190302ab44c46c0.png)
![](https://img.xkw.com/dksih/QBM/2022/1/16/2895941057585152/2896563462602752/STEM/a12e0e12-89e1-457a-b5ad-e92d59649197.png?resizew=468)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3806b2aba97557bc4aa84d6eb0144ba4.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cdd615843adf3e011e5b72f9c608bfa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ce50ba5e349425274f05d46d120a74.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】已知梯形
如图(1)所示,其中
,
,
,
,过点A作BC的平行线交线段CD于M,点N为线段BC的中点.现将
沿AM进行翻折,使点D到达点P的位置,且平面
平面
,得到的图形如图(2)所示.
![](https://img.xkw.com/dksih/QBM/2022/1/16/2895941057585152/2896563462602752/STEM/a12e0e12-89e1-457a-b5ad-e92d59649197.png?resizew=468)
(1)求证:
;
(2)若
,若点H为线段PC的中点,求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce0d7095ddd69d6ceaf1065b1bc2c79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/386c7de62e8f9a8161ebaefe6b4ec35e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73e4150583bb730627d98e250153a704.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50244defdb202cc420e1d6a910241c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392469b357b12b998528499929366c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53bdef2e7a7929ad6190302ab44c46c0.png)
![](https://img.xkw.com/dksih/QBM/2022/1/16/2895941057585152/2896563462602752/STEM/a12e0e12-89e1-457a-b5ad-e92d59649197.png?resizew=468)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3806b2aba97557bc4aa84d6eb0144ba4.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cdd615843adf3e011e5b72f9c608bfa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ce50ba5e349425274f05d46d120a74.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,在长方体
中,点E、F分别在
,
上,且
,
.
平面
;
(2)当
,
,
时,求平面
与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4305d8d52fe2cc79c78129652e64bb62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fccb37728702288d4be7148301ab685.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d26d8a9d64ad3c8cba28840b41ed7837.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f3e58edd1f900ca82bb2a3058293f52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab6bf42c7db96104456424e4d1be6c48.png)
您最近一年使用:0次
解答题-证明题
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(0.65)
名校
【推荐3】如图所示,圆台
的轴截面
为等腰梯形,
为底面圆周上异于
的点,且
是线段
的中点.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c407eeb34204a1df967b8fbe481cb04d.png)
平面
.
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e65ac334119ccd6204402a7aba29a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e53b212640dadf751ef7f65a78a209.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f94eef78bac237cad09fa9f3bef3965.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098a3e7d1f1890863b7483a98b618119.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa8efed521427404750045619c53b1ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c407eeb34204a1df967b8fbe481cb04d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895d6f710d5f67e1d4c7408d50d77281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edc9ffc43a56921fe79f8602636b8b0f.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edc9ffc43a56921fe79f8602636b8b0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23e2c643dd6501b20c46c5c6527a2634.png)
您最近一年使用:0次