and then,find the x/y=?
更新1:
How to divid by y²?
更新2:
but the ans is 2
更新3:
修正問題:2(x^2 - 3y^2)=xy ,then find x/y
Mathes question
回答 (2)
2013-10-27 4:15 am
✔ 最佳答案
2(x^2+3y^2)=xy and then,find the x/y=?Sol
Set p=x/y，y<>0
x=py
2(p^2y^2+3y^2)=py^2
2p^2+6=p
2p^2－p+6=0
p=[1+/-√(1－48)]/4
=(1+/-i√47)/4
題目改為
2(x^2－3y^2)=xy andthen，find the x/y=?
Sol
Set p=x/y，y<>0
x=py
2(p^2y^2－3y^2)=py^2
2p^2－6=p
2p^2－p－6=0
(2p+3)(p－2)=0
p=－3/2 or p=2
2013-10-27 1:45 am
2(x²+3y²)=xy
divid by y²
2[(x/y)²+3] = x/y
2(x/y)² - x/y + 6 = 0
Solve by [-b±√(b²-4ac)]/2a
x/y = [1+(√23)i]/4 or [1-(√23)i]/4
2013-10-27 14:33:31 補充：
這步有問題
2p^2－p－6=0
(2p+3)(p－2)=0
p=－3/2 or p=2
似乎是
2p^2－p－6=0
(2p－3)(p+2)=0
p=3/2 or p=－2
出唔到你要的 answer x/y = 2
divid by y²
2[(x/y)²+3] = x/y
2(x/y)² - x/y + 6 = 0
Solve by [-b±√(b²-4ac)]/2a
x/y = [1+(√23)i]/4 or [1-(√23)i]/4
2013-10-27 14:33:31 補充：
這步有問題
2p^2－p－6=0
(2p+3)(p－2)=0
p=－3/2 or p=2
似乎是
2p^2－p－6=0
(2p－3)(p+2)=0
p=3/2 or p=－2
出唔到你要的 answer x/y = 2
收錄日期: 2021-04-27 20:34:05
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20131026000051KK00124