Consider a quadratic equation x^2 + (1 - k)x + 625 = 0. If the roots of the quadratic equation are negative, find the range of possible values of k.
Ans: k <= 49
Inequality
2011-02-11 5:50 am
回答 (1)
2011-02-11 5:54 am
✔ 最佳答案
With the roots being real, we have:(1 - k)2 - 4 x 625 >= 0
(k - 1)2 >= 4 x 625
k - 1 >= 50 or k - 1 <= -50
k >= 51 or k <= -49
Then combining with -(1 - k) < 0 (since the roots are negative, their sum should be negative too)
1 - k > 0
k < 1
So combined together, we have k <= -49
參考: 原創答案
收錄日期: 2021-04-23 18:27:38
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110210000051KK01764