类比是探索发展的重要途径,是发现新问题、新结论的重要方法.阅读材料:
设
的两个根为
和
,那么
比较系数,可得
,
.
类比推广,回答问题:设
的三个根为
,
,
,那么
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/792bc89ffd9838256ad500160c598b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87f5b4a9dd507a0e9a8f81b149c2c0d7.png)
(___________)
(___________).
比较系数,可以得到一元三次方程的根与系数的关系:
___________,___________
,
___________.
设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/783a7b78d895784b4af75b962bd40f07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffe31f9b03474b1d5f1bcda7fe4f4182.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b092bd78e3c85db8ed4de2f4bff5f22c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bdc6c3be27e9ff44568939afbe78475.png)
类比推广,回答问题:设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e0e80a9c031053eea5e5c2de7f37500.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/792bc89ffd9838256ad500160c598b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87f5b4a9dd507a0e9a8f81b149c2c0d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf0159b286dc2f2b447e70c2d7e3f29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51ad4db954350cf179d7547fbf60d58d.png)
比较系数,可以得到一元三次方程的根与系数的关系:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83e590fa0b13ad3e9c9756642ef53a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d810b3771256ad982868a41e2775247.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cadab6e1b7d7b4eb50a636d58be1b3f7.png)
更新时间:2024-06-08 10:21:35
|
相似题推荐
解答题-计算题
|
适中
(0.65)
名校
【推荐2】计算:
(1) (-3x)2-2(3x-2)(x-3);
(2) 32 018×(-
)2 019 ;
(3) 2-1+(π-2)0+(-1)2 020
(4)解方程组:
(1) (-3x)2-2(3x-2)(x-3);
(2) 32 018×(-
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
(3) 2-1+(π-2)0+(-1)2 020
(4)解方程组:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec2d6762cc212291832822692071ef2a.png)
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解答题-问答题
|
适中
(0.65)
【推荐1】阅读材料:已知方程p2﹣p﹣1=0,1﹣q﹣q2=0且pq≠1,求
的值.
解:由p2﹣p﹣1=0,及1﹣q﹣q2=0可知p≠0,
又∵pq≠1,
∴p≠
.
∵1﹣q﹣q2=0可变形为
﹣1=0,
根据p2﹣p﹣1=0和
﹣1=0的特征,
∴p、
是方程x2﹣x﹣1=0的两个不相等的实数根,
则p+
,即
.
根据阅读材料所提供的方法,完成下面的解答.
已知:2m2﹣5m﹣1=0,
,且m≠n,求:
(1)mn的值;
(2)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d0e6dfb7980e2960dc2cde8f9341de.png)
解:由p2﹣p﹣1=0,及1﹣q﹣q2=0可知p≠0,
又∵pq≠1,
∴p≠
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5787f128a5a7fe474a5266bfe0f8e6e.png)
∵1﹣q﹣q2=0可变形为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6130c556c438393cb50cbcb8ee04a661.png)
根据p2﹣p﹣1=0和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6130c556c438393cb50cbcb8ee04a661.png)
∴p、
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5787f128a5a7fe474a5266bfe0f8e6e.png)
则p+
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5787f128a5a7fe474a5266bfe0f8e6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6b397e99528ab9a78e3262fc83ae869.png)
根据阅读材料所提供的方法,完成下面的解答.
已知:2m2﹣5m﹣1=0,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/619f68e49516e17784ab1ec98e692387.png)
(1)mn的值;
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1728eed8e2f6fc13baa8dda3f1c732cb.png)
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解答题-问答题
|
适中
(0.65)
【推荐2】已知关于
的一元二次方程
.
(1)当
为何值时,方程有两个不相等的实数根?
(2)若边长为5的菱形
的两条对角线
、
的长分别为方程两实根的2倍,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0871a0589afd80c90826b806cb5828b4.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(2)若边长为5的菱形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/20/87cbca36-1990-4b69-8030-f642ccb2731f.jpg?resizew=174)
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