如图,四边形
为正方形,
平面
,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/56f9c004-c77c-4557-9d93-91880d2be860.png?resizew=212)
(1)证明:平面
平面
;
(2)证明:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/56f9c004-c77c-4557-9d93-91880d2be860.png?resizew=212)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d98d25467d8a11ddeeb1e6e18eb704f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/422210c777ac0d625bbd81cc7601bf9b.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/466fabcaac59132fea648ff35342ec9d.png)
更新时间:2020-02-28 21:27:25
|
相似题推荐
【推荐1】如图,已知四棱锥
中,底面
为平行四边形,点
分别在
上.
,求证:平面
平面
;
(2)若点
满足
,则点
满足什么条件时,
平面
?并证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a5f302c1c2f7e1b46cad05594ed672e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bba2613c7a68fbe3478e4cf3dccf8fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/480eb43bbb9a6e3ef0c7cc491e860b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b28a07491270be75a3697538bec706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4bc5e89527a4e52c83ba66b388c3542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/982d01f052709b72afeaf1015fc7acc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d7ffa7d57cb72ca3468f448e70b52af.png)
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解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图:正方体ABCD-A1B1C1D1棱长为2,E,F分别为DD1,BB1的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/18/60878e38-b7e3-4e3a-9c9e-8bd906cfc333.png?resizew=160)
(1)求证:CF//平面A1EC1;
(2)过点D作正方体截面使其与平面A1EC1平行,请给以证明并求出该截面的面积.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/18/60878e38-b7e3-4e3a-9c9e-8bd906cfc333.png?resizew=160)
(1)求证:CF//平面A1EC1;
(2)过点D作正方体截面使其与平面A1EC1平行,请给以证明并求出该截面的面积.
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图所示,在四棱锥
中,
,四边形
为菱形,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/15/a6b7debb-9260-43ea-afa7-854cdfdedf6b.png?resizew=227)
(1)证明:
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dc178dde4cc43f65ef8cb2135d9bf66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/15/a6b7debb-9260-43ea-afa7-854cdfdedf6b.png?resizew=227)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08a9ec3b527947cad9caa4537e0cb7e7.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
名校
解题方法
【推荐2】已知矩形ABCD中,
,
,M,N分别为AD,BC中点,O为对角线AC,BD交点,如图1所示.现将
和
剪去,并将剩下的部分按如下方式折叠:沿MN将
折叠,并使OA与OB重合,OC与OD重合,连接MN,得到由平面OAM,OBN,ODM,OCN围成的无盖几何体,如图2所示.
;
(2)求此多面体体积V的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ffc2817fa590affb5a760a25dc65308.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fe95f656b98b53f71a9d72bf0c9a4b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4807ca16360c0cca436e59d4be98f626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a856daab95822013df31b1dd454e7696.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ed01d1ff5a7f21a68fb3a1e5c7f393e.png)
(2)求此多面体体积V的最大值.
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,在四棱锥P-ABCD中,底面ABCD是平行四边形,∠ACB=90°,PA⊥平面ABCD,
,
,F是BC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/03bf86d4-be07-4242-89cf-a390e5adc0b0.png?resizew=226)
(1)求证:AD⊥平面PAC;
(2)试在线段PD上确定一点G,使
∥平面PAF,请指出点G在PD上的位置,并加以证明;
(3)求平面PAF与平面PCD夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd893c4964b7f1ef69f0563d74c76d0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21ea52361458ce2e49ed0fe99d8e6c02.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/03bf86d4-be07-4242-89cf-a390e5adc0b0.png?resizew=226)
(1)求证:AD⊥平面PAC;
(2)试在线段PD上确定一点G,使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
(3)求平面PAF与平面PCD夹角的余弦值.
您最近一年使用:0次