but, why 2) is not right?
through it we can also get C作者: tongxun 时间: 2002-9-20 16:54
C is a wrong answer, because we can get a clear answer by the condition 1).
But if (a,b) means a certain point, you can use these numbers to check whether the curve is above the y zhou.作者: workhard77 时间: 2002-9-21 00:47
Sorry, I think you've misunderstand me. What i mean by "c" is not the answer "C" but the parameter C in the equality "y=x^2+c".
Maybe I did not express myself clearly.
Then, can you explain me why the answer "D" is not right?作者: workhard77 时间: 2002-9-21 00:59
But if (a,b) means a certain point, you can use these numbers to check whether the curve is above the y zhou.
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Why "y zhou"? I think we can get the number C by "c=y-x^2=b-a^2", that will be a certain number because (a, b) is certain. Then we can know whether y>0.
So condition 1) and 2) are all right by itself.
Why not "D"?作者: tongxun 时间: 2002-9-21 01:28
我误会了你的意思。你也误会了我的意思。我说“use these numbers to check whether the curve is above the y zhou.”就是指Y=C，可以通过此点求出。从而确定是否总在上访啊！
D作者: lcbfeng 时间: 2002-9-21 04:10
