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[不等式] 大大D水题,大神速来秒!!!

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零定义 posted 2014-7-18 14:30 |Read mode
Last edited by 零定义 2014-7-18 14:57证明或否定:若$\forall n\in N^*$,都有$$\sum_{k=1}^{n}\dfrac{1}{ak^2+bk+c}<\dfrac{1}{m}$$
                  其中 $a>0,2a+b>0,a+b+c>0$
                  则 $a(a+b+c)\ge m(m+a)$
睡自己的觉,让别人说去...

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kuing posted 2014-7-18 14:42
n=m=1, a=-1/2, b=c=0

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original poster 零定义 posted 2014-7-18 14:52
回复 2# kuing
是我自己输入出错...

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kuing posted 2014-7-18 15:11
回复 3# 零定义

缺少这么多关键信息……

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original poster 零定义 posted 2014-7-18 15:18
原谅我考虑不周嘛~N久没来了,代码都忘了,打着打着就忘了啥啥条件了

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睡神 posted 2014-7-19 16:45
k神呐,速来秒吧~背景明确,形式简洁,很适合你秒的~

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kuing posted 2014-7-19 21:21
啥背景啊

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original poster 零定义 posted 2014-7-20 13:15
回复 7# kuing
与极限有关?

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original poster 零定义 posted 2014-7-22 08:39
木要沉呀…顶上~求秒!!!
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其妙 posted 2014-7-25 10:36
等号都没有,难做呀

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