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mcfetridges
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Can you prove that 0!=1 or is it just an assumption?
AKG said:...then there's of course 1 way you can permute zero objects.
600burger said:It would make more sense that there would be infinte.
Gokul43201 said:Here's another : C(n,0) = number of ways of choosing 0 objects out of n = [itex]\frac{n!}{n!~0!} = \frac{1}{0!}[/itex]
So, it's useful to define 0! = 1. It allows you to do more math.
Factorial is defined a number of ways. I don't think it's a wrong definition to define it as the number of ways to permute things. As such, it's not metaphorical to say 0! is the number of ways to arrange nothing. It's literal, it's just based on a more simplistic, probably unconventional definition (used mostly to help people understand). The idea of arranging nothing, however, is not really nonsense, although I can see you might have trouble understanding at first. However, definitions like n! = n x (n - 1) x ... x 1 and definition by the Gamma function are better definitions. That's a different matter, however.600burger said:There are few things in math that "just are" but i would think this is one of them. All of this "arranging nothing" makes no sense, and feels more like a (and really is) metaphor to hep people understand, but metaphors are never exact replicas of the things they represent, or else they'd just be that thing!
I'm not sure you know what you're saying here. What exactly is it that will never happen? If factorial is defined in a more abstract sense, then there is no hypothetical event to speak of which we can say will never happen. If we define 0! by relating it to the Gamma function, what exactly isn't happening? On the other hand, if we say 0! is the number of ways of arranging zero things, what exactly is "not happening" there? The Greeks, I have read, had great trouble with the concept of zero, and thought that it made no sense to have zero as a number, so it would make no sense to say that you were adding 0 apples to the pile, nor did it make sense to have 5 + 0 = 5, since 0 wasn't an acceptable number, i.e. a number plus a number would always have to give a bigger number, that's how they thought "plus" should work. However, if that legend is true, then things that smart Greek mathematicians couldn't accept are things that children today can easily accept. I think there might be some conceptual difficulty in saying that 0! is the number of ways to permute zero things, but it's not a necessarily flawed notion.If anyone ever asks me this question i will just say "because it is". I find it to be pure convention. A made up defintion of something that will never happen so that we can go onto bigger and better equations.
600burger said:There are few things in math that "just are" but i would think this is one of them. All of this "arranging nothing" makes no sense, and feels more like a (and really is) metaphor to hep people understand, but metaphors are never exact replicas of the things they represent, or else they'd just be that thing!
If anyone ever asks me this question i will just say "because it is". I find it to be pure convention. A made up defintion of something that will never happen so that we can go onto bigger and better equations.
matt grime said:If we take n! as the number of bijections of a set of cardinality n, then 0!=1 makes perfect sense - there is only the empty function from the empty set to itself.
CTS said:Although 0! = 1 by definition only, here's a reason it makes sense using the recursive definition of factorial:
n! * (n + 1) = (n + 1)!
n! = (n + 1)! / (n + 1)
0! = (0 + 1)! / (0 + 1) = 1! / 1 = 1
GEB by Hofstadter said:Shuzan held out his short staff and said: " If you call this a short staff, you oppose its reality. If you do not call it a short staff, you ignore the fact. Now what do you wish to call this?"
Well, the "empty set" is counted as a set.
Is it really a stretch of the imagination to say there is just one way to make an empty product?
Who said anything about arranging nothing? I'm not even sure that makes grammatical1 sense! 0! counts the number of ways to arrange a collection with nothing in it. (i.e. a collection with zero objects). Here's one way to compute 0!:3trQN said:I understand the usefulness of factorials, but how do you justify that there is any numerical way to arrange nothing
It's easy to order the empty set. (In fact, there is exactly one way to do so) And the empty set certainly has properties. For example, [itex]\forall x: x \notin \emptyset[/itex].since you cannot create order from something that has no properties to order it by.
Your first equality only holds (by definition) for [itex](n-1) \geq 1[/itex]. Otherwise we can go on and say:Gib Z said:Finally, I was starting to think no one would post the proof CTS did, though this slight variation might be simpler.
[tex]n!=n\cdot (n-1)![/tex]
[tex]1!=1\cdot 0![/tex]
Since 1! equals 1, 0!=1.
No, in mathematics, 0 and 1 are two distinct numbers with different values. 0 represents nothing or absence, while 1 represents a single unit or entity.
In some cases, it may seem like 0 and 1 are equal, such as in the context of binary code, where 0 and 1 are used to represent off and on states. However, this is just a representation and not a mathematical equality.
The assumption is that there is a flaw or error in the mathematical logic or equations used to derive the statement. In other words, the assumption is that the statement is false and cannot be proven or supported by mathematical principles.
In mathematics, there are certain rules and properties that govern the relationships between numbers. One of these is the property of equality, which states that two numbers are equal if and only if they have the same value. Since 0 and 1 have different values, the statement "0=1" goes against this fundamental rule and is therefore considered illogical.
If 0 were to equal 1 in mathematics, it would lead to many contradictions and inconsistencies in mathematical principles and equations. This would greatly impact various fields that heavily rely on mathematics, such as science, engineering, and finance. Fortunately, the assumption that 0 does not equal 1 has been proven to be true and is widely accepted in the mathematical community.