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Primes (lemmy.ml)
submitted 3 years ago by to c/memes@lemmy.ml
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[–] 7 points 3 years ago (2 children)

2 is a prime number though…..

Is it Just because it’s the only even one?

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  • [–] 7 points 3 years ago (2 children)

    Often things hold true for all primes except 2. You come across things like "for all non two primes"

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  • [–] 4 points 3 years ago* (2 children)

    Any examples? Sounds like you mean the reason why one is excluded from the primes because of the fundamental theorem of arithmetic.

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  • [–] 3 points 3 years ago* (last edited 3 years ago) (1 child)

    No, he's right. "For any odd prime" is a not-unheard-of expression. It is usually to rule out 2 as a trivial case which may need to be handled separately.

    https://en.wikipedia.org/wiki/Fermat%27s_theorem_on_sums_of_two_squares

    https://www.jstor.org/stable/2047029

    https://www.jstor.org/stable/2374361

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  • [–] 1 point 3 years ago (1 child)

    It's not unheard of no, but if you have to rule out two for some reason it's because of some other arbitrary choice. In the first instance (haven't yet looked at the second and third one) it has to do with the fact that a sum of "two" was chosen arbitrary. You can come up with other things that requires you to exclude primes up to five.

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  • [–] 3 points 3 years ago (1 child)

    And how is "even" special? Two is the only prime that's divisible by two but three is also the only prime divisible by three.

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  • [–] 0 points 3 years ago (1 child)

    Well 2 is the outlier because it’s the only even prime. It might not be “special” but it is unique out of all of the prime numbers.

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  • [–] 1 point 3 years ago (1 child)

    "even" just means divisible by two. So it's not unique at all. Two is the only prime that's even divisible by two and three is the only prime that's divisible by three. You just think two is a special prime because there is a word for "divisible by two" but the prime two isn't any more special or unique in any meaningful way than any other prime.

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  • [–] 0 points 3 years ago (1 child)

    It’s unique because all the others are odd numbers. This is crazy that you’re trying to argue this.

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  • [–] 1 point 3 years ago (1 child)

    Of couse all the others are odd because otherwise they wouldn't be prime. All primes after three are also not divisible by three... "magic". The only difference is that there are is no word like "even" or "odd" for "divisible by three" or "not divisible by three".

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  • [–] 0 points 3 years ago

    only difference is that there are is no word like “even” or “odd” for “divisible by three” or “not divisible by three”.

    Yep, hence why 2 is unique - there is a word to describe numbers that are divisible by 2, and 2 is the only one of those that is a prime number.

    It seems that you don't know what the word "unique" means.

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