數學問題呀~
回答 (4)
✔ 最佳答案
y=(7/3)x+(5/3)/x
when y=-1
-1= (7/3)x+(5/3)x
-1= (12/3)x
-1=4x
x=-1/4
要通分母ar
參考: me
y = (7/3) x + (5/3) / x
當 y = -1,
-1 = (7/3) x + (5/3) / x
-3x = 7x^2 + 5 [左右乘3x]
7x^2 + 3x + 5 = 0
Δ = b^2 - 4ac
= 3^2 - 4(7)(5)
= -131
< 0
所以沒有實根
當y=-1的時候
-1 = (7/3)X + (5/3)X
-1 = (7X/3) + (5X/3)
-1 = (7X + 5X)/3
-3 = 12X
(-3/12) = X
X = -1/4
收錄日期: 2021-04-12 22:46:49
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061222000051KK04495
檢視 Wayback Machine 備份