如图,在四棱锥
中,
底面
,
,
,
,
,点
为棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/b050fd98-3b74-4f76-a550-1ab1157b577e.png?resizew=181)
(1)证明:
;
(2)求三棱锥
的体积;
(3)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.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/9060f03b9ee41d70d135b1e1a8902ce9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68d31600cba2d5256c7e78b6122d6755.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ba814113887c21637c1954f244812f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/b050fd98-3b74-4f76-a550-1ab1157b577e.png?resizew=181)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c38bbe49284a2ceab26001ced8cfd56.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb7ed85b76fb4c5e9a9a60bff4337742.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fba0dd982b283611f4d01be499546af9.png)
更新时间:2021-03-28 15:45:40
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,直三棱柱
的体积为
,
,
为
的中点,
为
的中点,
是
与
的交点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/24/c23d805a-15f6-4614-bbc0-4ebd1860ad73.png?resizew=190)
(1)证明:
;
(2)在线段
上是否存在点
,使得
平面
?若存在,请确定
的位置;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f90e17995e2f71e297d94ae51c7e5b1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/24/c23d805a-15f6-4614-bbc0-4ebd1860ad73.png?resizew=190)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e862713d078c4f06ec1f15ccd6f5a1f7.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a604466a9c8d10d557b3dfc43b547065.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8586897803243ec415350e91868850d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c4e7552a39c412d882766dbcd7eeb69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐2】已知
,
分别是
的边
,
上的一点,
,将
沿
折起为
,使
点位于
点的位置,连接
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/cf995c0d-8581-447e-a4c6-dea04711b8b8.png?resizew=173)
(1)若
,
分别是
,
的中点,平面
与平面
的交线为
,证明:
;
(2)若平面
平面
,
与
的面积分别为4和9,
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95a078495ba47076ccaa28b46f765d80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f460edcced5597615113c0fdc95b1dfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f07107087ce4abdfa5fc68fe6fb62f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a696a182fff038a86b2bbe8ca099442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/cf995c0d-8581-447e-a4c6-dea04711b8b8.png?resizew=173)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657dffbd3623b705f871878fbd9df57e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b025f10c28c8736d04418301637ba32f.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21dee56b9f36ba8f76fe67b76383636b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f460edcced5597615113c0fdc95b1dfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f656e1d1f68954e5f06de8958f6a9310.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d38593653bedb845ecfa820806a29a1e.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,在五面体
中,
,
平面
,
.已知
,
,
,且
.
平面
;
(2)求平面
与平面
的夹角的余弦值的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8bfe2553e852df73185d017c0a62fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62ab061ed9ec918926f1defceb85924a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c3e9ef3e849788645552cfb0735d987.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d927585a17c2e98ef7d5a9589a26ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f9b0421e0b4d74b22df706578b74a58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/563f3214a5f5ce732a91be9038ee0468.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c15e58659e6ee4d93650e2edb6d6f7ff.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,在多面体
中,四边形
为正方形,四边形
为矩形,平面
平面
,且
.
![](https://img.xkw.com/dksih/QBM/2021/4/1/2690587125612544/2691044641243136/STEM/cade9f35-7024-4475-862e-55988db2e83e.png?resizew=283)
(1)求证:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59e89556992cbfd7043330ac7421d342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd4b93d7abcfc4c3df48f03aa969c17f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2a4e3f0349fa83dc2a0b7d798f04843.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0997165a34c3bf2a0afe890db2bb5289.png)
![](https://img.xkw.com/dksih/QBM/2021/4/1/2690587125612544/2691044641243136/STEM/cade9f35-7024-4475-862e-55988db2e83e.png?resizew=283)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/662698361c6b3ddaf0c28a3c87be53e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14eec658f69c267a70c1e8f9b744e282.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/864689852707154e3a9be79f657f16d4.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】如图,在三棱柱
中,
,
,
,
在底面
的射影为
的中点,
是
的中点.
![](https://img.xkw.com/dksih/QBM/2022/1/9/2890852507148288/2893642062839808/STEM/67a9e563-2f13-44e1-88ac-8afff0213e22.png?resizew=181)
(1)证明:
平面
;
(2)求二面角
的平面角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ede6a60cad0e0b58e1549fda6e085719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4300aefd67369742e2b1ddcdc02dd495.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d0236d9dea89acb35d88f0857b38dbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb6892aaa5a3869ed87fe23add134d6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/035a5a88e7e2d6ef2b47d992412a1f2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/787ac5e13622afab5e9f8603afe42356.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/846a84e40de724b4c60a20c4faa194b9.png)
![](https://img.xkw.com/dksih/QBM/2022/1/9/2890852507148288/2893642062839808/STEM/67a9e563-2f13-44e1-88ac-8afff0213e22.png?resizew=181)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e8778aee92f0f2bf7c676e56625f00d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7d57ec09d1919cc372c301d0c5332a9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b43216f8150a0aedc3736c38171be0bb.png)
您最近一年使用:0次