Determine the nature of roots of the following equation.
4x^2-kx-5=0
F.4數學問題(二次方程)
2014-08-02 2:58 am
回答 (5)
2014-08-02 6:00 am
✔ 最佳答案
4x²-kx-5=0
D=√(k²+80)
因為k²是一個正數
所以√(k²+80)恆為正
故4x²-kx-5=0有相異兩個實數解
2014-08-02 7:40 am
為何未有指出兩根一正一負會扣一半分數??
2014-08-02 6:47 am
未有指出兩根一正一負,會扣一半分數。
2014-08-02 4:11 am
watch ur email now"!masterjik
2014-08-02 3:38 am
4 x² - k x - 5 = 0
Δ = (-k)² - 4(4)(-5) = k² + 80 > 0 if k is a real number
The roots are real and distinct.
2014-08-01 21:33:23 補充：
New Guy, replied your email already.
Some members told me that emails cannot be received these days, so if you do not receive my reply, maybe it is due to the system problem, or maybe I am busy to reply.
2014-08-01 23:05:41 補充：
呵呵～！！
有道理！！！
2014-08-02 21:57:59 補充：
因為一正一負也是可以推論出來的nature of roots，所以要作答此部份才算完整嘛！
Δ = (-k)² - 4(4)(-5) = k² + 80 > 0 if k is a real number
The roots are real and distinct.
2014-08-01 21:33:23 補充：
New Guy, replied your email already.
Some members told me that emails cannot be received these days, so if you do not receive my reply, maybe it is due to the system problem, or maybe I am busy to reply.
2014-08-01 23:05:41 補充：
呵呵～！！
有道理！！！
2014-08-02 21:57:59 補充：
因為一正一負也是可以推論出來的nature of roots，所以要作答此部份才算完整嘛！
收錄日期: 2021-04-17 23:59:20
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20140801000051KK00127