quadratic equation
回答 (2)
2009-10-09 12:46 am
✔ 最佳答案
The equation is x^2 - 3x + 1 = 0
2009-10-09 12:54 am
Method1:
Let the roots be x1 and x2
x1+x2=3
x2=3-x1
x1x2=1
x1(3-x1)=1
3x1-x1^2=1
x1^2-3x1+1=0
So the quadratic equation is x^2-3x+1=0
Method2:
You should know that given the sum of the roots and product of roots, the quardratic equation is x^2-(a+b)x+ab=0
So, the quardraric equation=x^2-3x+1=0
Let the roots be x1 and x2
x1+x2=3
x2=3-x1
x1x2=1
x1(3-x1)=1
3x1-x1^2=1
x1^2-3x1+1=0
So the quadratic equation is x^2-3x+1=0
Method2:
You should know that given the sum of the roots and product of roots, the quardratic equation is x^2-(a+b)x+ab=0
So, the quardraric equation=x^2-3x+1=0
收錄日期: 2021-04-25 22:37:27
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https://hk.answers.yahoo.com/question/index?qid=20091008000051KK00741