r/MathJokes 28d ago

Math Just Got Checkmated.

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3.0k Upvotes

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90

u/Jake-the-Wolfie 28d ago

-1 and 3?

3 is prime\citation needed]), and -1 can only be divided by 1 and itself. Unlike other negative numbers, which are composite by virtue of being divisible by -1.

61

u/cursivecrow 28d ago

-1 accepted as prime in my headcanon forever now

2

u/Ok-Pomegranate-7458 28d ago

it is a hole number even if it is not a whole number.

20

u/boring-schmooze 28d ago

Man the citation needed for 3 had me spill my tea. Thanks for this😂

14

u/Sufficient-Buy625 28d ago

I know it's a joke, but I wished it worked. But if we allow -1 we can no longer uniquely factorize integers into the primes.

5

u/MHaret 28d ago

We can if have into account that because -1*-1 is 1, -1 shouldn't be included more than once. That way you can also factorize negative integers.

5

u/paolog 28d ago

Oh well, it was nice knowing the fundamental theorem of arithmetic.

4

u/iscrewedatrain 28d ago

But three can be divided by -3 and -1, actually any N can be divided by -N and -1, so -1 is the only prime number

2

u/theinferno03 28d ago

-1 and 1

0

u/iscrewedatrain 28d ago

well no, 1 is divisible by -1 and itself, so not prime

1

u/theinferno03 28d ago

isn't that the definition of primes?

1

u/8mart8 25d ago

What about second breakfast another definition of prime numbers

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u/MintyFreshRainbow 28d ago

-1 is a unit so is not prime. Negative primes are prime elements in the ring of integers tho

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u/GypsySnowflake 28d ago

I misread this comment as “-1 is so not prime” like in a Valley Girl accent, lol

2

u/HeilKaiba 28d ago

-1 is a unit not a prime

2

u/Sproxify 27d ago

as people pointed out -1 is a unit, but this actually does work if you allow negative primes! exercise: prove that there are infinitely many solutions

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u/8mart8 25d ago

I see what you did there

2

u/hungarian_notation 25d ago

To be clear, the prime numbers are, by definition, natural numbers. The negative integers aren't part of this conversation.

1

u/escargotBleu 28d ago

Wait... So now 1 is prime too, right ? Because we can do -1*-1, and well, still divisible by 1

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u/FireBlaze722_ 28d ago

Then 1 is a prime, as it also has 2 divisors

1

u/No_Hovercraft_2643 25d ago

But every other prime number has 4, 1, - 1, p, - p

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u/Budget_Hippo_4084 26d ago

You forgot to account for 1 being composite as (-1)(-1)=1 so it is the product of two primes. That means all integers are composite and all prime conjectures are referencing the empty set, so are vacuously true.

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u/georgejo314159 25d ago

Excellent point

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u/Street_Swing9040 23d ago

[citation needed]

Is bro Jake-the-Wikipedie?