Latest Posts by dynmaxblaze - Page 2

Yes.

Suppose 2n/(n-2) is an integer. Call it k. Then 2n = (n-2)k. But notice also that (n-2)×2 = 2n-4. So 2n is divisible by n-2, and so is 2n-4. So their difference, 4, is also divisible by n-2.

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To see this, subtract the two equalities above. You'll get 2n - (2n-4) = (n-2)k - (n-2)×2, or, simplifying, 4 = (n-2)(k-2), so 4 is divisible by (n-2)

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The only (positive integer) factors of 4 are 1, 2, and 4. So n-2 has to be 1, 2, or 4, and thus n has to be either 3, 4, or 6.

The question asks only for positive integers, but it would be a mistake to exclude the negatives. If we take negatives into account also, then -4, -2, and -1 also work, for which we get n to be -2, 0, and 1. And notice here that 1, although reached via a negative, is in fact a positive integer solution.

So the only numbers are 1, 3, 4, 6.

For more information on this, this kind of question comes under a part of math called Number Theory.

Does anyone know if 3, 4, and 6 are the only positive numbers for which 2n/(n-2) is an integer or are there more?

They discovered Busy Beaver Five!

BB(5) = 47,176,870

https://discuss.bbchallenge.org/t/july-2nd-2024-we-have-proved-bb-5-47-176-870/237

I remember being in elementary school and feeling a deep alienation at people’s just vicious rejection of mathematics, the reason being, like

It’s like. A classic approach to hypothetical communication with aliens that you start with the things you know you have in common and proceed from there. Mathematics is that.

Imagine you approach someone you don’t understand with a thing specifically designed to be something they and you can agree on as a starting point for communication and they just react with “yeah i hate this”

A lot of people absolutely fail to distinguish between 'I hate this because I was taught this badly' and 'I hate this because this thing is inherently bad', and I hate it.

you know I absolutely agree with the fact that the education system is fucked and traumatises students. I absolutely agree with the fact classes like english and maths and history can be piss boring and teach you nothing of worth and could be a trigger depending on how hellish of a teacher you were given.

Hell, the only reason I love maths is because I primarily engaged with it outside of class and found it fun on my own terms. I'm still bitter towards my history teachers for having clear favourites and not engaging half the class.

but like. if you're railing against the *subjects* themselves, refusing to learn any of the basics as an adult, and bringing up how much you hate them at every opportunity? At some point that becomes a problem you have to deal with yourself.

and if you don't, you're going to be the reason this happens again for the next generation.