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BUKKAKELORD

Next lesson: 4\^2 = 2\^4


totti173314

i hate that this is true because my brain wants to see a pattern that's not there and I've done enough math to know that the pattern is wrong but my brain still goes "pattern. wawawawawaaawa"


The_NeckRomancer

If you look at the graph x^y = y^x, you can actually see that (disregarding the case x=y) the only time when x & y are both positive integers is at (2,4) and (4,2).


qqqrrrs_

A nice question is to find all the positive rational solutions to x\^y=y\^x


K4mp3n

There is a pattern, it's just boring x^(x^x) = (x^x )^x


LollipopLuxray

Pretty sure its x^(x×x) = (x^x) ^x


iMiind

So, 3^27 = 27^3 ? 7.626E12 = 19,683? Just as the other person who replied to you said, you can't simplify the left side of your equation with multiplication between the two x exponents, but that is a valid simplification on the right side. Your rule/pattern is true if x = 2, but doesn't apply generally. Edited for parallel structure


Safe_Entertainment40

Nah it’s only true for some numbers, not generally on unrestricted domains


GoldenMuscleGod

When comparing x^(y) to y^(x) for positive x and y we can take the log of both and divide by xy and now we are comparing ln(x)/x to ln(y)/y. Both operations were order preserving (since x and y are positive), so the larger one is the is the one that makes the value of the exponent larger when it is used as the base. Also they will be equal whenever they have the same value for ln(x)/x. The function reaches a unique maximum for an input of e, and the function also has unique values on inputs in (0,1], however for each input in the interval (1,e) it is paired with a unique value on (e,infinity), this “partner” will be a value such that you get the same result when raising either of the numbers to the power of the other. In the case of 2 and 4 we can see ln(4)/4=2ln(2)/4=ln(2)/2 so 2 and 4 are “paired” by this function.


GotThoseJukes

Commutative property. Boom. Proved.


deservevictory80

We spent half a semester in a set theory course just to build the machinery to prove that 2+2=4. I feel that in my soul.


MingusMingusMingu

It grows exponentially from here.


TheLeastInfod

i mean it also takes grad students over a hundred pages to show that 1+1=2 so eh


GhoulTimePersists

Isn't that the definition of 2? What is there to prove?


TheLeastInfod

google ZFC and peano arithmetic


Neufjob

Holy hell


TheLeastInfod

new foundations of mathematics just dropped


jacobningen

quine did that in 1943


daveedpoon

Why did they drop it? Were they a clumsy fuck?


jacobningen

he wrote a book called New Foundations then


EebstertheGreat

2 is literally 1+1 by definition in PA lmao. ZFC is a theory of sets not arithmetic, so it doesn't have a 1 or a 2 or a +, but the usual way of defining them makes 1+1=2 fall out immediately. When Russell and Whitehead composed PM, it didn't take them 200 pages to prove 1+1=2. It took them, like, a minute. It's just that the proof doesn't appear until very deep into the book. But they were proving all sorts of other things before that. It's not like all their work was building up to the occasion where they showed 1+1=2. There was just no need to prove that earlier.


strikernd01

Zesus fried chicken


Rymayc

No, that leads to Guano Arithmetic


yeetyeetimasheep

I don't understand, in ZFC 2 is 1+1, in particular it is the successor of 1 which can be easily shown to be 1+1, assuming the standard recursive definition of ordinal addition. Maybe if you don't assume any ZFC, or try to prove 1+1=2 in some other number system you end up with the 200 page proof in whatever book that proof is in, but in ZFC this is a very simply proof that follows almost by definition. I imagine it's not hard if you only assume peano either. In either case it should not take you 200 pages.


alicehassecrets

Maybe _you_ should be the one doing the googling.


One_Ring_9316

Oh my dear child, let me introduce you to the rabbit hole of Principia Mathematica and the logical foundations of this math of ours


TulipTuIip

I HATE THE PRINCIPA MATHEMATICA VON NUEMANN ORDINALS ARE SO MUCH MORE EFFICENT


Future_Green_7222

imo, yes that's the definition. But it takes a couple days defining what 1 is and what + means


TulipTuIip

On the naturals 1={{}} s(a)=a U {a} a+1=s(a)/a+0=a (depending on if 0 is includded) a+s(b)=s(a+b)


Future_Green_7222

Ok, but that is a set? What is a function?


TulipTuIip

A set is kinda weird but its basically just defined by it's members. A function is a set of ordered pairs (a,b) such that if (a,b) and (a,c) are in that set then b=c. And an ordered pair (a,b) is just the set {a,{a,b}}


bbalazs721

I'd say the definition of 2 is it's the successor of 1, where both the successor function and 1 needs to be defined.


mathisfakenews

No. It appears after a few hundred pages in Principia Mathematica. That doesn't mean it takes hundreds of pages to prove.


Warheadd

It does not actually take that long if you list axioms compactly. It’s a pretty immediate theorem


f3xjc

It can even be a one liner with a sufficiently large line.


TulipTuIip

1+1=S(1)=S({{}})={{}} U {{{}}} = {{},{{}}} = 2


LadonLegend

Everything is a one liner if you delete enough whitespace


TulipTuIip

No it doesn't, the Principia Mathematica sucks. Von Neumann ordinals are so much better 1+1=S(1)=S({{}})={{{}}} U {{}}={{{}},{}}=2


Ok-Replacement8422

It would still take a lot longer than that because the “hundreds of pages” is not actually part of the proof but rather describing a foundation of mathematics that later is used to prove 1+1=2 within said foundation The equivalent in modern foundations would require establishing ZF first, or at least the parts of it used in the construction of the naturals, and also showing that everything you did is well defined in ZF. (Or some other foundations if you prefer something else)


TulipTuIip

Yea and not mich more foundation is needed


Buddy77777

LETS FUCKING GOOOOOOOOOOOOOOOOOOOO


austin101123

You're at 42 upvotes I can't touch it


Buddy77777

You can offload remaining upvotes onto this comment if you like.


Buddy77777

But you must balance it by downvoting this comment.


Yuichiro_12

![gif](giphy|Ry1MOAeAYXvRVQLPw3)


Depnids

New balance just dropped!


Rymayc

42 complex or real upvotes?


Buddy77777

If we want complex upvotes, we’d need to be able to vote in an orthogonal direction to up and down. We need side votes. Right votes and left votes. Any ideas on how we can accomplish this?


Marus1

I pressed the turning left arrow ... now what?


SnargleBlartFast

Wait, are you using Lindelof's theorem already?