1 . 某机器有四种核心部件A,B,C,D,四个部件至少有三个正常工作时,机器才能正常运行,四个核心部件能够正常工作的概率满足为
,
,且各部件是否正常工作相互独立,已知
,设
为在
次实验中成功运行的次数,若
,则至少需要进行的试验次数为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2fd0129b4e654a99a94f7e3ded77a37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fccf604219eaa58dbfc99ddeae091b98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed49735005eaa5f98d4406a337f0a996.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb95dd39049f4660abcc5cb8cddd87ff.png)
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2 . 已知函数
,
,函数
的图象在点
处的切线为
,
与两坐标轴交点分别为
,
;在点
的切线为
,
与两坐标轴交点分别为
,
.若两条切线互相垂直,则下列变量范围正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff003550d99ab3862156a75df7f18521.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9f2d09f468b67d20a2d6b60794cefb0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8674b8c449a74c37fef3407f2ffcd582.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f9c0002b13f6cae093cd9dc9f19941b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d17bec7c34bd729548e08554fb2d60a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a01c29fe42abf2ad8661c8f53355939.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/758080793e3ca0b8166f840475434aa9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05fa33d01dac1a688927a606b693d57f.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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