四面体的一条棱长是
,其余棱长都是
.考虑满足题意四面体如图所示:取
,其余棱长为1.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/fa788563-93ca-4537-a684-6ed31c3e0d1f.png?resizew=170)
(1)把四面体的体积
表示成
的函数
;
(2)求
的值域和单调区间.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa41f80c6e33393a9f7bb57fca6b493.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/fa788563-93ca-4537-a684-6ed31c3e0d1f.png?resizew=170)
(1)把四面体的体积
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
更新时间:2022-02-15 08:30:48
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】用一张边长为a的正方形硬纸板,在四个角裁去边长为
的四个小正方形,再折叠成无盖方盒.当裁去的小正方形边长
发生变化时,纸盒的容积
会随之发生变化.问:
(1)求
关于
的函数关系式;
(2)
取何值时,容积
最大?最大值是多少?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
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【推荐2】传说《西游记》中孙悟空的“如意金箍棒”原本是东海海底的一枚“定海神针”.作为兵器,“如意金箍棒”威力巨大,且只有孙悟空能让其大小随意变化.假定孙悟空在使用“如意金箍棒”与各路妖怪打斗时,都将其变化为底面半径为4
至10
之间的圆柱体.现假定孙悟空刚与一妖怪打斗完毕,并降伏了此妖怪,此时“如意金箍棒”的底面半径为10
,长度为
.在此基础上,孙悟空使“如意金箍棒”的底面半径以每秒1
匀速缩短,同时长度以每秒40
匀速增长,且在这一变化过程中,当“如意金箍棒”的底面半径为8
时,其体积最大.
(1)求在这一变化过程中,“如意金箍棒”的体积
随时间
(秒)变化的解析式,并求出其定义域;
(2)假设在这一变化过程中,孙悟空在“如意金箍棒”体积最小时,将其定型,准备迎战下一个妖怪.求此时“如意金箍棒”的底面半径.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97153bc3d02dfb38ee046487a8037a41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97153bc3d02dfb38ee046487a8037a41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97153bc3d02dfb38ee046487a8037a41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/605aefd43658521db901986c2e2d12d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97153bc3d02dfb38ee046487a8037a41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97153bc3d02dfb38ee046487a8037a41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97153bc3d02dfb38ee046487a8037a41.png)
(1)求在这一变化过程中,“如意金箍棒”的体积
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c0fc398ffae36ca13db9912ec8d6aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)假设在这一变化过程中,孙悟空在“如意金箍棒”体积最小时,将其定型,准备迎战下一个妖怪.求此时“如意金箍棒”的底面半径.
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解答题-问答题
|
适中
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解题方法
【推荐3】如图,在半径为10cm的半圆形(
为圆心)铝皮上截取一块矩形材料
,其中点
、
在直径上,点
、
在圆周上.
![](https://img.xkw.com/dksih/QBM/2021/3/26/2686185288400896/2687172182827008/STEM/445208efebd64e109587652fa7f3a379.png?resizew=199)
(1)怎样截取才能使截得的矩形
的面积最大?并求最大面积
(2)若将所截得的矩形铝皮
卷成一个以
为母线的圆柱形罐子的侧面(不计剪裁和拼接损耗),应怎样截取,才能使做出的圆柱形罐子体积最大?并求最大体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/2021/3/26/2686185288400896/2687172182827008/STEM/445208efebd64e109587652fa7f3a379.png?resizew=199)
(1)怎样截取才能使截得的矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若将所截得的矩形铝皮
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
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解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图1所示,在等腰梯形
中,
,
,垂足为
,
,
.将
沿
折起到
的位置,使平面
平面
,如图2所示,点
为棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/8f54cdf7-b2da-42fb-b22f-31157e1d6980.png?resizew=327)
(1)求证:
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5acb763021bf166ca719d07223591d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/497846628a41a9bc750a645e045afb47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a398397362a18da1cc9f24bf3f356ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/065f2c3527fcc9d84939c47ac8640643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24ba44e8746668d15ff9abb4598f2caa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/675d7fbe782edce4a585e75a9d78e2bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd8168bac8b10cad2ead420a392fdef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01ff27eea7545bb06f9472f91290c54e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/8f54cdf7-b2da-42fb-b22f-31157e1d6980.png?resizew=327)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79157098473116de9b59f4281011a93a.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eb278a0241c7a3887def5d88cf7383c.png)
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|
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(0.65)
名校
【推荐2】如图,在正三棱柱
中,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c9f23207b67eba6a74de672076c946b.png)
,
、
分别为
与
的中点.
(1)求异面直线
与
所成角的大小;
(2)求四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c9f23207b67eba6a74de672076c946b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ff6c9099d36b2bbd7f5a47531942de2.png)
![](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/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
(1)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93ecad355286188fd317939fa50f9555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
(2)求四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ce90a191972ebaf07b2f80c2a6c263f.png)
![](https://img.xkw.com/dksih/QBM/2018/7/6/1982229989515264/1983313830830080/STEM/f2b7ad0de97544e68a6ce8d7759e734c.png?resizew=152)
您最近一年使用:0次