如图,四棱锥
中,底面
为菱形,
面
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/d36408da724c46a2b024a2277b6d6fd0.png)
(1)求证:
平面
;
(2)设
,
,
,求点
到平面
的距离.
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/bbabb7754bfb4ba8b6b1a85c9c3d3627.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/881e49286115432fa8b6e211e0af32e6.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/62d4e4222d3e44cd9018e26d39f26cb2.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/881e49286115432fa8b6e211e0af32e6.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/57a4f787663145f5b7bfc0ecb202eca3.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/fede770a0d914d4cb21e9b6d52d4b296.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/d36408da724c46a2b024a2277b6d6fd0.png)
(1)求证:
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/334319b6e5f4406296901e01acd9e397.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/05ed8c64171140af989f94238103f79c.png)
(2)设
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/e946906caaab45a486fff27f1b580f47.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/f4fe43d69722499f997ea2d5196f12df.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/37b76889e5f547f291ce4318dc25a8c1.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/fa16256839814123ab502079aae7de21.png)
![](https://img.xkw.com/dksih/QBM/2016/3/7/1572521169772544/1572521176088576/STEM/9b75ed901f4f4637bc482da2cd397cbe.png)
更新时间:2016-12-04 03:17:17
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,在三棱锥
中,底面
为等边三角形,
,且平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/3/33867e2d-8aed-46dd-8962-c2497a241f28.png?resizew=163)
(1)求三棱锥
的体积;
(2)求二面角
的余弦值;
(3)判断在线段
上是否存在点Q,使得
为直角三角形?若存在,找出所有符合要求的点Q,并求
的值;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/708b366bf964b84e46dbf4b074c4b1e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/3/33867e2d-8aed-46dd-8962-c2497a241f28.png?resizew=163)
(1)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e820aec9c1a975242fe6d76408a9cde8.png)
(3)判断在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7a551505ae42b49904bab59b17012d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/412b394ab196e93ba49f115d0a8cacd6.png)
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2】如图所示,在棱长均相等的平行六面体
中
分别为线段
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/20/55444ffb-64db-4ee4-8765-a3692606418e.png?resizew=168)
(1)设
,请以向量
表示
;
(2)求证:平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05d1641ee630d23b48c7d179d09b40d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2695585c5bccde7f9b49d92ca0d3916.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/20/55444ffb-64db-4ee4-8765-a3692606418e.png?resizew=168)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dfb9769a14ebf5cbc5fa0c06ce96435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae951e0bb5a2a406f1572fc1e4964265.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae54940f33b8714da5fe3b7546f8b3dc.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba0fbd88fdb064072eedd136e9cb41ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
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解答题-证明题
|
适中
(0.64)
【推荐1】如图1,在△
中,
,
为
中点,
于
,延长
交
于
.将△
沿
折起,得到三棱锥
,如图2所示.
![](https://img.xkw.com/dksih/QBM/2016/5/31/1572677790146560/1572677796093952/STEM/9c729c9b81f34a479ad7fa4d98830b17.png)
(Ⅰ)若
是
的中点,求证:
∥平面
;
(Ⅱ)若平面
平面
,试判断直线
与直线
能否垂直?并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dde6182c16084365446aac3c4475d808.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6863529cecdf22e3488ab99d75f89d90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b97b7e45a628d3e5b4d42ce924dce28.png)
![](https://img.xkw.com/dksih/QBM/2016/5/31/1572677790146560/1572677796093952/STEM/9c729c9b81f34a479ad7fa4d98830b17.png)
(Ⅰ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15a424b50eaeafa6f302ffd95476cb86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
(Ⅱ)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c53647b9072e89d95914d7b532ff18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.64)
【推荐2】已知长方形
中,
,
,
为
中点,将
沿
折起到△
,所得四棱锥
,如图所示.
![](https://img.xkw.com/dksih/QBM/2016/11/24/1573173583667200/1573173589385216/STEM/f037eb090746458aaad27628b4c1477f.png)
(1)若点
为
中点,求证:
平面
;
(2)求
的体积;
(3)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a88c44f558705de3bcefcfc0ece96b8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a7d5cf4f2bf91fe0f7a99f2ba358c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37793a3a810e823e10c340986f55ddd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b25935591138805029bb8b9ac5510862.png)
![](https://img.xkw.com/dksih/QBM/2016/11/24/1573173583667200/1573173589385216/STEM/f037eb090746458aaad27628b4c1477f.png)
(1)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f369bec2d5682bf6b8b317a08aff546.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37793a3a810e823e10c340986f55ddd.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b25935591138805029bb8b9ac5510862.png)
(3)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/446cc49254e4d42f09f96f8089ca4aa9.png)
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