F.4 Maths

2013-10-04 6:30 pm

Given that α and α – 2 are the roots of the equation x2 + (3k – 2) x + 48 = 0. (a) Find the values of α(b) If α>0, find the value of k.

更新1:

why product of roots is α^2 - 2α = - 48

回答 (4)

2013-10-04 7:30 pm

✔ 最佳答案

(a) product of roots= α^2-2α=48
α^2-2α-48=0
(α-8)(α+6)=0
α=8 or -6
(b) sum of roots= 2α-2=-(3k-2)
3k=4-2α
k=(4-16)/3
k=-4

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2013-10-05 5:15 am

The product of roots should be +48.

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2013-10-05 3:15 am

For ax²+bx+c=0, product of roots = c/a.

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2013-10-04 9:50 pm

why product of roots is α^2 - 2α = - 48

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