If K and W are the roots of the quadratic equation 5x^2-7x+c= and K:W=, find the possible value(s) of c
If the difference between the roots of 4x^2+2KX-5=0 IS 3, find the possible value(s) of k.
F4 Nature of roots
2011-10-07 4:44 am
回答 (3)
2011-10-08 8:25 am
✔ 最佳答案
#1Let the roots = 3m and 4m respectively,
3m+4m = 7/5 => m = 1/5
c/5 = (3m)(4m)
c = 5*3*4(m^2)
c = 60/25 = 12/5
#2
Let the roots be n,m, i.e. n < m
m - n = 3
(m-n)^2 = 9
m^2 - 2mn + n^2 = 9
m^2 + 2mn + n^2 - 4mn = 9
(m+n)^2 - 4mn = 9
(-2k/4)^2 - 4(-5/4) = 9
4k^2 / 16 + 5 = 9
k^2 / 4 = 4
k^2 = 16
k = +/-4
參考: Hope the solution can help you^^”
2011-10-07 6:18 am
Q.1 K : W = ? : ?
2011-10-07 5:00 am
Something are missing in the first question.
收錄日期: 2021-04-13 18:17:20
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