1 . 目前发射人造天体,多采用多级火箭作为运载工具.其做法是在前一级火箭燃料燃烧完后,连同其壳体一起抛掉,让后一级火箭开始工作,使火箭系统加速到一定的速度时将人造天体送入预定轨道.现有材料科技条件下,对于一个
级火箭,在第
级火箭的燃料耗尽时,火箭的速度可以近似表示为
,
其中
.
注:
表示人造天体质量,
表示第
(
)级火箭结构和燃料的总质量.
给出下列三个结论:
①
;
②当
时,
;
③当
时,若
,则
.
其中所有正确结论的序号是___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0532411d57ea180b894ad7ecc3c3cd2.png)
其中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cbc231de2cd997f8abb79585f057f48.png)
注:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1448ec3239cfb8c7872e101ab7405e6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/476d6d49c2989ac6cfd0c06149df251c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7600d2cfbdc6146db96cc545706004f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2429b6a233ef2f66677b15bc11a13294.png)
给出下列三个结论:
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dc1c64bd18987615bd40f41d4cf4a7c.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87b351f16728b0023fd63678f8103c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/493102857cb6471c2d1f2e35c3872b55.png)
③当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc2d3df37e73a8abea815f37dbb3fff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46ca25328bd480836d66a2b33b41b00f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb5becaecdd2a5481cf52f31e4930368.png)
其中所有正确结论的序号是
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2 . 如图,在直角三角形
中,
,
垂直于斜边
,且垂足为
,设
及
的长度分别为
和
,
是
的中点,点
绕点
顺时针旋转
后得到点
,过
点作
垂直于
,且垂足为
.有以下三个命题:
①由图知
,即可以得到不等式
;
②由图知
,即可以得到不等式
;
③由图知
,即可以得到不等式
;
以上三个命题中真命题的是______ .(写出所有正确命题的序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8e9ec412ea0355e4e5cd06c60e5fee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e87f673c8f5c214d1e59bfe21fe82397.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2ff7caec4fdd8fb54a3ffbff9692414.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7e4fa04825ac7d071968056322d88be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
①由图知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31367f0685c866fb013012c699803a35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/160414ad552f0f114a6bc92bcf000270.png)
②由图知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7ffac6c07b3208f1ab97386df03b617.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b22fa0018340c11558c0ef8dbe422cb0.png)
③由图知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddff7f3e7ba78336d8b9d96d0065e1db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/516372020f70ab0b86e02f96f3e684e1.png)
以上三个命题中真命题的是
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/26/e5b38708-1c30-46c5-b816-773546683593.png?resizew=188)
您最近一年使用:0次
3 . 对于三元基本不等式请猜想:设![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec197b8ab457cfee3d4733f3d7f8d6f3.png)
_________ ,当且仅当
时,等号成立(把横线补全).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec197b8ab457cfee3d4733f3d7f8d6f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44acc0ee22dc4b7750e8be825e7c1355.png)
您最近一年使用:0次