F.4 Maths

2013-10-01 8:46 pm

Suppose k and k-3 are the roots of the quardratic equation x^2 - 3kx + h = 0. find the values of h and k.
ans is h=18, k=-3

回答 (1)

2013-10-01 9:00 pm

✔ 最佳答案

sum of roots =-b/a
product of roots =c/a

k+k-3=-(-3k)/1
2k-3=3k
-3=k
k=-3

k(k-3)=h/1
-3(-3-3)=h/1
-3(-6)=h
18=h
h=18

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