Qu.15答案乜唔係C咩?
Qu.32答案乜唔係D咩?
07 HKCEE Maths M.C.Qu. 15&32
2007-05-08 2:42 am
回答 (3)
2007-05-08 2:47 am
✔ 最佳答案
15. C32. ax+by+1=0
when x=0
by+1=0
y=-1/b
Because y-intercept is negative, so b is positive
b>0
when y=0
ax+1=0
x=-1/a
Because x-intercept is negative, so a is positive
a<0
2008-10-09 8:19 am
2007-05-08 2:51 am
Q15係C
Q32係A
你先將佢change subject
-ax 1
y= ------- - -------
b b
-1/b係y-int... 因為佢y-int係-ve...所以b要係+ve
-a/b係slope.....睇返個圖...slope係-ve
而b係大過0....a>0先可以令slope變-ve
所以a,b>0
2007-05-07 18:52:37 補充：
y= -ax/b - 1/b
Q32係A
你先將佢change subject
-ax 1
y= ------- - -------
b b
-1/b係y-int... 因為佢y-int係-ve...所以b要係+ve
-a/b係slope.....睇返個圖...slope係-ve
而b係大過0....a>0先可以令slope變-ve
所以a,b>0
2007-05-07 18:52:37 補充：
y= -ax/b - 1/b
收錄日期: 2021-04-23 16:59:34
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070507000051KK03303