Is 0^0 Equal to 1? An Explanation of Mathematical Concepts and Terminology

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In summary, there is a convention that 0^0 is equal to 1, although it may not be well-defined in all cases. This convention is often used in mathematical proofs and allows for simplification and reduction of special cases. Some mathematicians argue that this convention is useful and makes sense in certain contexts, while others argue that it violates the rules of exponents. Ultimately, it is up to the individual mathematician to decide whether to use this convention or not.
  • #71
Hurkyl said:
Let a be a number such that a^a=a/a

a^a=a/a
a^(a-1)=1/a
a^(a-1)=a^-1
a-1=-1
a=0.

Ah, the classic fallacies of forgetting your hypotheses, and reversing the flow of logic.

The very premise of your problem requires a to be a positive number. (0 is not a positive number)

Also, what you have proved is
If a is a (positive) number satisfying [itex]a^a=a/a[/itex], then a = 0​
which is very different from
If a=0, then [itex]a^a = a/a[/itex].​


Nevermind the fact that he/she divided by a in the derivation, and took a logarithm of both sides (which also happened to remove the a = 1 solution).

dimension10 said:
0^5=1*0*0*0*0*0
0^4=1*0*0*0*0
0^3=1*0*0*0
0^2=1*0*0
0^1=1*0
0^0=1

Thus,

0^0=1.

0^5=17*0*0*0*0*0
0^4=17*0*0*0*0
0^3=17*0*0*0
0^2=17*0*0
0^1=17*0
0^0=17

Thus,

0^0=17?​
 
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  • #72
:smile: Citation : " We have not seen the last of the Power Less monster ! " :smile:
 
  • #73
Mute said:
0^5=17*0*0*0*0*0
0^4=17*0*0*0*0
0^3=17*0*0*0
0^2=17*0*0
0^1=17*0
0^0=17

Thus,

0^0=17?

But aren't powers defined that way? I mean,

3^5=1*3*3*3*3*3
3^4=1*3*3*3*3
3^3=1*3*3*3
3^2=1*3*3
3^1=1*3
3^0=1

Isn't that why any number taken up to the power of 0 is 1?
 
  • #74


Hurkyl said:
This argument only makes sense if exponentiation is repeated multiplication. This is why the convention [itex]0^0=1[/itex] works very well when plugging 0 into a polynomial or Taylor series, because the exponentiation there is repeated multiplication. (and for the same reason it is often used in algebra and combinatorics)

However, the exponentiation operator on real numbers is not repeated multiplication, and continuity is rather important for calculus and real analysis, which is why real exponentiation leaves [itex]0^0[/itex] undefined.

Oh, ok. I did not know that.
 
  • #75


Hurkyl said:
The very premise of your problem requires a to be a positive number. (0 is not a positive number)

You are right. I think I forgot that 1^1=1/1

1=0 :smile:

I guess it is a form of zero proof?
 
  • #76
So, should we conclude that the answer is different when you look at it from different perspectives? I presume 0 is not a number but just a concept.
 
  • #77
dimension10 said:
So, should we conclude that the answer is different when you look at it from different perspectives?
More accurately, the answer is different when you change what the symbols mean.

I presume 0 is not a number but just a concept.
Where did you get that idea? :confused:
 
  • #78
Ashwin_Kumar said:
The evidence micromass pointed out is sufficient. The idea that [tex]0^{0}=0[/tex] doesn't make sense.

You cannot say it does not make sense because, viewing it as a limit, it is true in the sense of limit x approaches 0 0^x=0.

In fact, we could claim that it does not make sense to carry out operations with 0 or an extreme number like infinity, since it easily runs into paradoxes.
 
  • #79
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  • #80
0 is not a counting number (aka "positive integer") but it is a number. I don't think that "answers.yahoo.com" is a very good source of technical information.
 
  • #81
Wow, my respect for yahoo answers is suddenly much lower...
 
  • #82
The way I like to look at this is that for any equation of the type y=k^x then for all finite values of k,y tends to unity as x tends to zero,even when k tends to zero.I am unable to see any reality in the limiting case where k and x become zero but that's probably just me,I have forgotten most of my maths.:confused::smile:
 
  • #83
HallsofIvy said:
0 is not a counting number (aka "positive integer") but it is a number. I don't think that "answers.yahoo.com" is a very good source of technical information.

Its not the only place I saw that. I've also seen it written in the publications "When is Arithmetic meaningful?" and "The story of 0".
 
  • #84
dimension10 said:
Its not the only place I saw that. I've also seen it written in the publications "When is Arithmetic meaningful?" and "The story of 0".

Non of which are mathematics texts.

I agree that 0 was a bit of controversial number and it took a long time before it was accepted. However, over 99.99999999999% of the mathematicians today see 0 as a number, just like 1, -1, pi and i are numbers (and not just concepts).

There will of course be people who disagree with 0 being a number, which is a philosophically valid point of view. But it's not the point of view of current mathematics.

Remember, there are also people that believe the Earth is flat. So you can't just accept whatever people say... You must form your own opinion by thorough research.
 
  • #85
micromass said:
Non of which are mathematics texts.

I wish you were right. I've seen some math texts that regard 0 as a natural number and some that don't.
 
  • #86
gb7nash said:
I wish you were right. I've seen math texts that regard 0 as a natural number and some that don't.

Yes, yes, of course. There's a bit of a disagreement wether 0 is a natural number. But everybody agrees that 0 is a number (=integer, rational number, real number, complex number) and not just a concept.
 
  • #87
micromass said:
Non of which are mathematics texts.

I agree that 0 was a bit of controversial number and it took a long time before it was accepted. However, over 99.99999999999% of the mathematicians today see 0 as a number, just like 1, -1, pi and i are numbers (and not just concepts).

There will of course be people who disagree with 0 being a number, which is a philosophically valid point of view. But it's not the point of view of current mathematics.

Remember, there are also people that believe the Earth is flat. So you can't just accept whatever people say... You must form your own opinion by thorough research.

gb7nash said:
I wish you were right. I've seen some math texts that regard 0 as a natural number and some that don't.

Why is it not possible to consider 0 the absence of a number, rather than a number itself?
micromass said:
Yes, yes, of course. There's a bit of a disagreement wether 0 is a natural number. But everybody agrees that 0 is a number (=integer, rational number, real number, complex number) and not just a concept.

The product of a transcendental number with another non-transcendental number should give a transcendental number. But pi multiplied by 0 is 0. 0 is certainly not transcendental.
 
  • #88
dimension10 said:
Why is it not possible to consider 0 the absence of a number, rather than a number itself?
What would that even mean?




The product of a transcendental number with another non-transcendental number should give a transcendental number. But pi multiplied by 0 is 0. 0 is certainly not transcendental.[/QUOTE]
Then why even mention it? No one has suggested that 0 was a transcendental number.
(And it it certainly NOT true the the product of a transcendental number and a non-transcendental number is a transcendental number. I have no idea what you mean by "should give".)
 
  • #89
dimension10 said:
Why is it not possible to consider 0 the absence of a number, rather than a number itself?

OK, what do you consider to be "a number"? Do you think -1 is a number? What about pi or i?


The product of a transcendental number with another non-transcendental number should give a transcendental number. But pi multiplied by 0 is 0. 0 is certainly not transcendental.

Why "should" this be the case? You don't have the power to tell mathematics what is true and what's not! (this was said to me by my high school teacher who thought I was complaining too much, I've used the phrase ever since :smile: )
 
  • #90
HallsofIvy said:
What would that even mean?



dimension10 said:
The product of a transcendental number with another non-transcendental number should give a transcendental number. But pi multiplied by 0 is 0. 0 is certainly not transcendental.
Then why even mention it? No one has suggested that 0 was a transcendental number.
(And it it certainly NOT true the the product of a transcendental number and a non-transcendental number is a transcendental number. I have no idea what you mean by "should give".)



micromass said:
Why "should" this be the case? You don't have the power to tell mathematics what is true and what's not! (this was said to me by my high school teacher who thought I was complaining too much, I've used the phrase ever since :smile: )

Well, I mean that:

2pi is transcendental.
3pi is transcendental.
4pi is transcendental.
...
22993.341486513pi is transcendental.

Is there any number that does not follow this rule? Isn't a transcendental number defined as an irrational number that is not the multiple of any 2 or more numbers?
 
  • #91
micromass said:
OK, what do you consider to be "a number"? Do you think -1 is a number? What about pi or i?

I think that 0 is just a "landmark" on the field of numbers. All numbers are calculated with respect to 0. E.g. -1 is defined as a number with difference 1 from 0 in a certain direction (the negative direction).
 
  • #92
dimension10 said:
Isn't a transcendental number defined as an irrational number that is not the multiple of any 2 or more numbers?

No, a transcendental number is defined as a number which is not the root of a polynomial

[tex]a_nX^n+...+a_1X+a_0[/tex]

with an,...,a0 rational.

That said, it is true that q=0 is the only rational number such that q*pi is not transcendental. But that's hardly a good reason to exclude 0 from being a number!

Without 0, we wouldn't have integers (because what would 1+(-1) be?), and without integers, we would have very ugly things. And mathematics would be pretty useless.
 
  • #93
dimension10 said:
I think that 0 is just a "landmark" on the field of numbers. All numbers are calculated with respect to 0. E.g. -1 is defined as a number with difference 1 from 0 in a certain direction (the negative direction).

I really don't understand why you consider -1 a number, but 0 not. You can't have -1 without having 0!

And 0 is a much more natural concept than -1. Say that I have 8 apples and I give 8 apples away, then I have 0 apples left. What's the problem with this?
 
  • #94
micromass said:
I really don't understand why you consider -1 a number, but 0 not. You can't have -1 without having 0!

And 0 is a much more natural concept than -1. Say that I have 8 apples and I give 8 apples away, then I have 0 apples left. What's the problem with this?
Langauge constraints thought. :frown: Negative numbers and zero have different linguistic hurdles to overcome.

With negative numbers, we have to overcome our language's preference to express everything in terms of "magnitude and direction". e.g. to reject the notion of "a surplus of -5" because one would simply say "a deficit of 5".

With zero, we have to overcome our language's preference for using negation. e.g. to reject the notion of "traveled a distance of 0 meters" because one would simply say "didn't travel".

(disclaimer: I am not a psychologist, nor have I actually studied the phenomenon. However, the observation does appear to fit observed fact, and the underlying cause is plausible)
 
  • #95
micromass said:
Without 0, we wouldn't have integers (because what would 1+(-1) be?), and without integers, we would have very ugly things. And mathematics would be pretty useless.

I am not saying that 0 does not exist. I am saying that 0 is not a number.
 
  • #96
For example, if you say that a=b+0, we do not say that a and be are unequal do we?
 
  • #97
2 is not a prime number. Every other prime number is odd, only 2 stands out. 2 ought to be odd. But it isn't.

So I would say that 2 is more of a "curiosity" than a prime number.
 
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  • #98
dimension10 said:
I am not saying that 0 does not exist. I am saying that 0 is not a number.

dimension10 said:
For example, if you say that a=b+0, we do not say that a and be are unequal do we?

Replace "b plus 0" with "b times 1". Ergo 1 is not a number!
 
  • #99
pwsnafu said:
Replace "b plus 0" with "b times 1". Ergo 1 is not a number!

b multiplied by 1 means 1 times of b. Means if you put b 1 time you get 1, right? So, 1 is a number.
 
  • #100
disregardthat said:
2 is not a prime number. Every other prime number is odd, only 2 stands out. 2 ought to be odd. But it isn't.

So I would say that 2 is more of a "curiosity" than a prime number.

But the definition of a prime number, is that, it has only 2 factors. 2 has 2 factors and is thus a prime numbers.
 
  • #101
dimension10 said:
But the definition of a prime number, is that, it has only 2 factors. 2 has 2 factors and is thus a prime numbers.

I have provided a sound argument as compared to yours, that "0 is not a number because it does not share a certain property with all other rationals". Believe me, every rational has some property not shared with all other rationals.

2 does similarly not share a property with all other primes, but this provides no basis for denying that 2 is a prime number.

What I'm most interested in is what you consider "a number" is. It is essentially a conventional label (which leaves it up to personal, or more correctly, collective opinion), and no argument could prove that 0 is not a number. This applies to the primes as well. The definition "a natural number which is divisible only by 1 and itself is a prime" corresponds to "an element of Q is a number". We don't leave out 2 as a prime by the same type of reason we don't leave out 0 as a number.
 
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  • #102
dimension10, what exactly is your definition of a number?
 
  • #103
dimension10 said:
Means if you put b 1 time you get 1, right?

:rolleyes: I think my brain melted...

disregardthat said:
What I'm most interested in is what you consider "a number" is.

micromass said:
dimension10, what exactly is your definition of a number?

Thirded. I too would like to know.
 
  • #104
dimension10 said:
b multiplied by 1 means 1 times of b. Means if you put b 1 time you get 1, right? So, 1 is a number.
No, you get b.
 
  • #105
disregardthat said:
2 is not a prime number. Every other prime number is odd, only 2 stands out.

Doesn't that make 2 rather odd?
 

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