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1/0 是infinity 还是无解。
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发表于 9-6-2005 03:12 PM
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发表于 9-6-2005 03:12 PM
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发表于 11-6-2005 12:15 PM
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在复变数函数论中,有人定义1/0为无穷,并为无穷定下一些运算法则.一般就说无定义 |
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发表于 11-6-2005 10:24 PM
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发表于 12-6-2005 01:04 AM
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发表于 15-6-2005 08:07 PM
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[1]
如果1/infinity = 0
那么 0* infinity = 1!
而且 1/0 = infinity 是对的!?!!??
[2]
再来,如果 1/0 = K
那么, 0 * K = 1?
显然, K = 无解!!!
[3]
换一个角度;
1粒西瓜平均分给0个人; 那每人可得多少?
显然,只有1粒西瓜, 所以答案不可能是无限(infinity)!
因此, 答案只有无解!?!?!?!?!?!! |
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发表于 16-6-2005 12:45 PM
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无解。infinity 只是一个概念,比如说 x + 1 > x, x 非无限, 可是 inf + 1 > inf 是没有意义的.
[2] (proof by contradiction) 就说明了并不存在任何一个数 k,使到 1 / 0 = k 成立.
可是若取极限,那么 lim_(x -> 0) 1 / x = infinity 是成立的. |
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发表于 16-6-2005 08:55 PM
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允许我引用一段英文,摘录自 Lars V. Ahlfors (第一届 Fields 奖得主) 所著的 Complex Analysis
For many purposes it is useful to extend the system C of complex numbers by introduction of a symbol 8 (不会打) to represent infinity. Its connection with the finite numbers is established by setting a+8 = 8+a = 8 for all finite a, and b.8=8.b=8 for all b not equal zero including b=8. It is impossible, however, to define 8 + 8 and 0.8 without violating the laws of arithmetic. By special convention we shall nevertheless write a/0 = 8 for a not equal zero and b/8 =0 for b not equal 8. |
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发表于 19-6-2005 07:07 AM
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infinity
1/0.1 = 10
1/0.01 = 100
1/0.00001 = 100000
1/0.0000000000001 (approaching 0) = 100000000000000 (approaching infinity)
ok? |
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发表于 19-6-2005 05:51 PM
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kensai 于 19-6-2005 07:07 AM 说 :
infinity
1/0.1 = 10
1/0.01 = 100
1/0.00001 ...
那1/-0.00000000000000001 =-infinity
1/0 = + infinity 还是 -infinity呢? |
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发表于 20-6-2005 05:38 PM
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fritlizt 于 19-6-2005 05:51 PM 说 :
那1/-0.00000000000000001 =-infinity
1/0 = + infinity 还是 -infinity呢?
那 就 看 lim 1/x 时 , x -> 0+ 还 是 x -> 0- |
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发表于 20-6-2005 08:12 PM
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无限大的定义:大于任意实数m的数
不是很好的解释,只是记忆中有这样的一种定义,表达方式不太好 |
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发表于 20-6-2005 09:39 PM
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一个类比,请问虚数在现实中存在吗? 可是,虚数在工程上的用途却是广泛的.同理,无穷并非一个存在的数,却在某些领域有其实用之处. |
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发表于 20-6-2005 10:46 PM
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