If the solution of x in {y=x^2 -kx+k y= -x+17/4 is the reciprocal of the other, find the values of y.
thx!!!!!!!!!
maths 中5
2012-10-21 10:03 pm
回答 (1)
2012-10-21 10:20 pm
✔ 最佳答案
y = x^2 - kx + ky = -x + 17/4
So,x^2 - kx + k = -x + 17/4
x^2 + (1 - k)x + k - 17/4 = 0
As the roots are reciprocal
k - 17/4 = 1
k = 21/4
x^2 - (17/4)x + 1 = 0
4x^2 - 17x + 4 = 0
(4x - 1)(x - 4) = 0
x = 4 or 1/4
The values of y is 4 or 1/4
收錄日期: 2021-04-27 17:45:44
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20121021000051KK00234