名校
解题方法
1 . 《易经》中的“太极生两仪,两仪生四象,四象生八卦”充分体现了中国古典哲学与现代数学的关系,从直角坐标系中的原点,到数轴中的两个半轴(正半轴和负半轴),进而到平面直角坐标系中的四个象限和空间直角坐标系中的八个卦限,是由简单到繁复的变化过程.现将平面向量的运算推广到
维向量,用有序数组
表示
维向量,已知
维向量
,
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8715a3f984d2627afd7c40c61347b7cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57bfff3d191a90414aa2f318c5e9f40b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8715a3f984d2627afd7c40c61347b7cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f2535413bedb71226ef984bd73c5ca0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a6b8e9510e5024fbf88747b8710f54c.png)
A.![]() | B.![]() |
C.![]() | D.存在![]() ![]() |
您最近一年使用:0次
2023-03-26更新
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1476次组卷
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5卷引用:四川省绵阳中学2023届高三适应性考试(三)理科数学试题
名校
解题方法
2 . 如图1,与三角形的三边都相切的圆叫做三角形的内切圆.设O是△ABC的内切圆圆心,
内是△ABC的内切圆半径,设
是△ABC的面积,
是△ABC的周长,由等面积法,可以得到
内
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/e3da696e-d797-4178-ab24-f0087aafa165.jpg?resizew=358)
(1)与三棱锥的四个面都相切的球叫做三棱锥的内切球.设三棱锥的体积是
,表面积是
,请用类比推理思想,写出三棱锥的内切球的半径公式
内(只写结论即可,不必写推理过程);
(2)如图2,在三棱锥
中,
,
,
两两垂直,且
,求三棱锥
的内切球半径和外接球的半径之比.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5cbff84327e964f912a54032e76ccc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8c261982132e55c19fd25ad50c6f3b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4fcc80a88cb1dc8fd4184f5b8225814.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/e3da696e-d797-4178-ab24-f0087aafa165.jpg?resizew=358)
(1)与三棱锥的四个面都相切的球叫做三棱锥的内切球.设三棱锥的体积是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
(2)如图2,在三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50094bfee564d9c1b03088ac2ece28c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
您最近一年使用:0次
2021-12-29更新
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442次组卷
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3卷引用:四川省南充市白塔中学2022-2023学年高三上学期入学考试数学(理)试题