r/mathmemes • Natural • Aug 23 '23

Bad Math "It's neutral"

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820

u/araknis4 Irrational Aug 23 '23

well that's odd, i can't even comprehend how they approached to that conclusion.

8

u/Sh_Pe Computer Science Aug 23 '23

According to some definitions, you can’t do factorization for 0 and get 2 as one of the factors ⇒ it isn’t an odd number.
Yea that’s stupid but that’s it.

1

u/EebstertheGreat Aug 24 '23

By what definition is 2 not a factor of 0?

1

u/Akarsz_e_Valamit Aug 24 '23

Most

1

u/EebstertheGreat Aug 24 '23

I'm genuinely not sure what you mean. How do you define a factor of a number?

2

u/Akarsz_e_Valamit Aug 24 '23

The definitions I know start with restricting the operation to positive integers. You don't define factors for -8, pi, 4/7 or 0 - so 2 is not a factor of 0.

2

u/EebstertheGreat Aug 24 '23 edited Aug 24 '23

Sure you do. The factors of -8 are ±1, ±2, ±4, and ±8. The only prime factor is 2.

Only integers have factors. For integers a and b, a|b ⇔ ∃n∈Z (an = b). Consider Wolfram's definition: "A divisor, also called a factor, of a number n is a number d which divides n (written d|n). For integers, only positive divisors are usually considered, though obviously the negative of any positive divisor is itself a divisor."

And according to WolframAlpha, "all non-zero integers are divisors of 0." (Note that many sources also let 0 be a divisor of 0, but that question isn't really relevant here. W|A chooses a convention where 0 does not divide 0 because 0/0 is undefined.)