題目是 m + nx - x^2=0 x=1 or -1/2
求m和n
P.S" (^)系指2次方
以下系我既解,,但系錯左...錯d咩???
m + n(-1/2) - (-1/2)^2=0.......................(1)
m + n(1) - (1)^2=0............................(2)
(1), m + n(-1/2) - (-1/2)^2=0
4m-2n+1=0
m=(2n-1)/4.....................(3)
Put (3) in (2),
(2n-1)/4 + n(1)- (1)^2=0
2n - 1 + 4n=4
n=5/6 m=1/6
正確答案系n=1/2 , m=1/2
做錯呢條1元2次方程
2007-09-14 7:31 am
回答 (2)
2007-09-14 7:36 am
✔ 最佳答案
in equation (1), m + n(-1/2) - (-1/2)^2=0
4m-2n - 1=0 <-- NOT +1
2007-09-14 9:08 am
(1), m
4m-2n+1=0<<<呢度錯(-1/2)^2 應該係 1/4
正確應該係:
m + n(-1/2) - (-1/2)^2=0
m+n(-1/2)-1/4 =0
4m-2n-1=0
m=(2n+1)/4.....................(3)
Put (3) in (2),
(2n+1)/4 + n(1)- (1)^2=0
2n+1+4n-4=0
n=1/2
Then, M=1/2
4m-2n+1=0<<<呢度錯(-1/2)^2 應該係 1/4
正確應該係:
m + n(-1/2) - (-1/2)^2=0
m+n(-1/2)-1/4 =0
4m-2n-1=0
m=(2n+1)/4.....................(3)
Put (3) in (2),
(2n+1)/4 + n(1)- (1)^2=0
2n+1+4n-4=0
n=1/2
Then, M=1/2
收錄日期: 2021-04-13 13:28:08
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070913000051KK04693