#General Formula for all arithmetic operations
1 messages · Page 3 of 1
Okay
this is right right
Yeah
RoyalBanana
$ln(a) = e^{ln(ln(a))}?$
RoyalBanana
Cancels
$ln(a) = ln(a)?$
RoyalBanana
let's gooo it works
Yup
RoyalBanana
Let's try to find a formula for $ln^n_k(x)$
RoyalBanana
like we just did for $ln^2_k(x)$
Hmm
RoyalBanana
RoyalBanana
$ln^1(x)=?$
RoyalBanana
$log^n_a(H(n,a,b))=b$
RoyalBanana
$ln^1(b)=b-e$
RoyalBanana
RoyalBanana
$ln^1_k(x)=x-ke$
RoyalBanana
ooh that's what this was yeah
$ln^1_k(x)=e*-k+x$
$ln^2_k(x)=e^{(-k)}*x$
$ln^3_k(x)={}^{(\ln^4(x)-k)}e$
RoyalBanana
*ln^4 not ln
I have figured it out
$ln^1_k(x)=e*(ln^2(x)-k)$
$ln^2_k(x)=e^{(ln^3(x)-k)}$
$ln^3_k(x)={}^{(\ln^4(x)-k)}e$
RoyalBanana
$ln_k^n(x)=H(n+1,e,ln^{n+1}(x)-k)$
RoyalBanana
RoyalBanana
Nice
$H(n,e,ln^n(b))=b$
RoyalBanana
So $H(n+1,e,ln^{n+1}(x))=x$
RoyalBanana
$H(n+1,e,ln^{n+1}(x)-k)=ln_k^n(x)$
$H(n+1,e,ln^{n+1}(x))=x$
RoyalBanana
RoyalBanana
$H(n+1,e,ln^{n+1}(H(n+1,e,0))-k)=ln_k^n(H(n+1,e,0))$
RoyalBanana
$H(n+1,e,-k)=ln_k^n(H(n+1,e,0))$
RoyalBanana
$H(n,e,k)=ln_{-k}^{n-1}(H(n,e,0))$
RoyalBanana
$H(n,a,b)=log_{a,{-b}}^{n-1}(H(n,a,0))$
RoyalBanana
Using this formula, I did some maths and figured out H(0,a,b)=b+1
yup
b+1
noice!
So that time I inputted n=1 imma do n=0 now!
You're not gonna like this
It gave me H(-1,a,b)=b+1
I really don't think there's a way around this
Know what I'm manually finding a way around this
You're right this does not make sense
Oh
You did a lot of stuff
Maybe we kinda need to reconstruct the formula
I did some research and I found that 1+b should be 1+ 1+1+1+…1 b times, and this would reduce the unary operation into an operation with kinda nothing. It doesn’t really make sense H(1,a,2) should be H(0,a,a) which is a?a. Now I see, it’s 2 by definition. But what would H(1,a,1) be? It doesn’t really make sense to me that this is a, because the complexity breaks down to addition, we can’t break down addition, because it’s one of the most abstact operations we know (if we don’t think outside the box). We could just continue this to get the successor and then just nothing, (maybe the assigment operation. By definition you’re right, but by addition logic it’s a bit diffrent
1 + 1+1 … b copies?
The formula is made on the fact that you cannot break down addition, but we want to find a general formula
RoyalBanana
That means it probably wouldn't work for n=0 either
Probably
I think I get why you can't go below b+1
see with like b+a or b*a depending on a, the number of times it's being repeated is different
but with b+1 it's not
you cant have something being repeated turn into b+1 bc that would mean there would be a value for it to change from into b+1 after so many repetitions, but b+1 never changes based on a
lemme give example
a*b can be turned into something being repeated a times bc it depends on a
a+a+a+a... you can change the number of a's around
but how do you do that with b+1? you can't change the a value you can't change the number of a's
anyway what the heck does it mean to have H(2.5,a,b) lol
somewhere inbetween multiplication and exponentiation?
Actually I suppose I could generalize the way I figured it out but for any n
Nice it worked!
I got $H(n-1,a,b)=H(n,a,log^n_a(b)+1)$
RoyalBanana
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$16={}^{3}2$
RoyalBanana
yup
this reminds me of that formula we had
${}^{(log_a^s(x)-k)}a=log_{a,k}(x)$
RoyalBanana
yup checks out!
Nicee
I think I there is a Problem in pit previous calculations
This
Wait
It‘s not (e^^2)^^(log(e^^2)s(e) - 1), it‘s (e^^2)^(log(e^^2)s(e) - 1)
And maybe it’s Not even a super log in there, not sure
Nicee, so it‘s a?b = a + (log^1(a)(b) + 1) ?
2?4 = 2 + (2 + 1)
2?4 = 5?
RoyalBanana
RoyalBanana
Hmm
Thats kinda sad because it ignores the a but I guess we can‘t do anything about it
Operations with non integer n would be cool
Nicee
How to make a half step, maybe 0.5 of an Operation to another one?
This one does a full step
There Must be some value for k that does a Full step and then use it to make a half step, like we saw with lnk and lns
RoyalBanana
now I wonder if I can get rid of a too
That -1, from Operation to and other integer Operation. Can we reach the non integer operations by adjusting k?
Sure
But with this you have to know either the log or the H operation to figure out the other
it's impossible to figure out both from knowing nothing
with this formula
Yeah true
We need some formula for H(n+k,a,b)
then we can extend it to non integers
and also H(n,a,b+k)
Hmm
Ye that's basically this kinda
do you see the problem
Yeah I know
What if we try to analyze the structure of log. We know ln(e)(e^^e) = lns(e^^e), so what if ln^2(x)(e^^e) = lns(e^^e)
I guess ln^2(e)(e^e) = ln(e^e), and ln^2(e^e)(e^e^e) = ln(e^e^e)
$ln^2_x({}^ee)=e^{(-x)}*{}^ee$
RoyalBanana
Oh
Wait did you mean ln3 instead of lns on the second one
so it's one more the left one
No, I wanted to know how to jump from multiplication to tetration to find the pattern
Just jump from multiplication to exponentiation to tetration
Hmm, so what would x need to be so it equals e?
But don’t we need the steps to find the pattern and then find the non integer operations?
RoyalBanana
how would that help though
So we know what do we need to input for k in lnk(e) so we get ln^3.5(e) or something
you'd need to invent a new formula first so do that first
$x=-ln(e/{{}^ee})$
RoyalBanana
$x=-(ln(e)-ln({}^ee))$
RoyalBanana
$x={}^{(e-1)}e-1$
Hm, oh okay
RoyalBanana
Ooh I see where you're going
What would your strategy be to find non integer operations?
Nicee
Lemme think for lns it’s 1, for ln it’s e, and for ln^2 it’s e^^(e-1) -1
I was thinking that since we have a definition of H(n+1,a,b) in terms of H(n,a,b) we could find a definition of H(n+k,a,b) in terms of H(n,a,b), and then just plug in non integer k values to that
Oh
Yeah true
So that would mean we could repeat H(n,a,b) k times
Like log with k
?
yeah!
^^^^^^^
I wonder if H(-0.5,a,b) would be different than H(0.5,a,b)?
Or would it get stuck in the same way that H(-1,a,b)=H(0,a,b)
That would be very interesting, maybe it could be like the factorial, where all negative integers equal infinity but the non integer numbers equal a real number
interesting
anyway what do you think of this it would be useful^
Though we would need notation to distinguish which part is being repeated
Like the difference between these
$H(n,a,H(n,a,b))$
$H(n,H(n,a,b),b)$
$H(H(n,a,b),a,b)$
RoyalBanana
Hm
Maybe we can just choose one to be the definition Im 99% sure the bottom one is useless and decently sure the middle one is
The top one is the one used in the recursive formula anyway
Oh my god this gives the new problem of $H_\frac{1}{2}(n,a,b)$ lmao
RoyalBanana
^
Oh yea
yes
definitely
Remember this
well we can rewrite it
with this
How?
$H(n,a,b)=H(n-1,a,H(n,a,b-1))$
RoyalBanana
RoyalBanana
So we could use this for Hk ?
RoyalBanana
Nicee, but it would change n only by -1
We're getting there
Then we can repeat that formula
but first we gotta put it in H_k notation otherwise it'd be a headache
I think the notation should be like this lemme give an example
$H_3(n,a,b)=H(n,a,H(n,a,H(n,a,b)))$
RoyalBanana
Wait
How do you write this with h_k the last one is n not n-1..
Wait
Ohh
duh
Uhhhh
Just set that last H(n,a,b-3) as the b in this H_k formula
Ahh
$H(n,a,b)=H_3(n-1,a,H(n,a,b-3))$
I think I see
RoyalBanana
See, b in H_k basically gets ignored until the very end
Yeah
Ofc
3 isnt special here!
$H(n,a,b)=H_k(n-1,a,H(n,a,b-k))$
RoyalBanana
Interesting
RoyalBanana
neat
alrr
What would be this H(n,a,H(n-1,a,b)) ?
Soo.. $H(n-1,a,b)=H_k(n-2,a,H(n-1,a,b-k))$
RoyalBanana
RoyalBanana
H(n,a,0) at least for n whole, is 1 if n isn't 1, if n=1 then it's a
for n whole and n not equal to 1: $H(n,a,b)=H_b(n-1,a,1)$
RoyalBanana
Oh wait
if n=2 then it's 0
for n=1: $H(1,a,b)=H_b(0,a,a)$
for n=2: $H(2,a,b)=H_b(1,a,0)$
for n integer and not equal to 1 or 2: $H(n,a,b)=H_b(n-1,a,1)$
interesting
RoyalBanana
What is the b on the Hb good for?
?
H(n,a,0) is very simple
It repeats and then gets H(n,a,b)
but the point is that chooseing k=b leads to H(n,a,0) which allows this, basically getting rid of the H(n... part
so it's only in terms of H(n-1...
Very nice
So if we have this formula thing
for n=1: $H(1,a,b)=H_b(0,a,a)$
for n=2: $H(2,a,b)=H_b(1,a,0)$
for n integer and not equal to 1 or 2: $H(n,a,b)=H_b(n-1,a,1)$
RoyalBanana
Let's plug in H(n-1,a,1)
for n-1=1: $H(1,a,b)=H_1(0,a,a)$
for n-1=2: $H(2,a,b)=H_1(1,a,0)$
for n-1 integer and not equal to 1 or 2: $H(n-1,a,1)=H_1(n-2,a,1)$
RoyalBanana
Aka
for n=2: $H(1,a,1)=H(0,a,a)$
for n=3: $H(2,a,1)=H(1,a,0)$
for n integer and not equal to 2 or 3: $H(n-1,a,1)=H(n-2,a,1)$
Interesting
RoyalBanana
checks out
Ah remember this
#1330832852819906661 message
works the same way the lnk rule works
I was gonna use the formula again on H_b(n-1,a,1) which is why I started with using the formula on H(n-1,a,1)
too see if there's a pattern
We need a formula for $H_k(n,a,b)$ like this..
RoyalBanana
What part of it?
There would need to be some Hb that equals H(n-1,a,0) i think
Btw I just thought of something
$H_1(n,a,H_{-1}(n,a,b))=H_0(n,a,b)=b$
so $H(n,a,H_{-1}(n,a,b))=b$
but also $H(n,a,log^n_a(b))=b$
so $log^n_a(b)=H_{-1}(n,a,b)$
RoyalBanana
interesting
Wait
ofc $H_{-1}(n,a,H_{-1}(n,a,b))=H_{-2}(n,a,b))$
but also now that we know that $log^n_a(b)=H_{-1}(n,a,b)$
$H_{-1}(n,a,H_{-1}(n,a,b))=log^n_a(log^n_a(b))=log^n_{2a}(b)$
Therefore $H_{-2}(n,a,b))=log^n_{2a}(b)$
RoyalBanana
does that make Sense
This is cool
Waitttttt! Ofc also $H_{-1}(n,a,H_{-2}(n,a,b))=H_{-3}(n,a,b))$
but also now that we know that
$log^n_{a}(b)=H_{-1}(n,a,b)$ and
$log^n_{2a}(b)=H_{-2}(n,a,b)$
$H_{-1}(n,a,H_{-2}(n,a,b))=log^n_a(log^n_{2a}(b))=log^n_{3a}(b)$
Therefore $H_{-3}(n,a,b))=log^n_{3a}(b)$
RoyalBanana
Lemme say it a different way
RoyalBanana
On the left side we plug in log(2a)(n)(b) instead of b and on the right side we plug in H(-2)(n,a,b) instead of b
and we can do that since they're equal
hope that makes sense
?
Wait where's this coming from?
Because it‘s like you Said with the H, H-1(n,e,H-1(n,e,b)) = H-2(n,e,b) = log(2e)(b)
RoyalBanana
So anyway $H_{-3}(n,a,b))=log^n_{a,3}(b)$
RoyalBanana
I have a quick other question. What would x be if log^4(e,x)(e^e) = log^3(e,1)(e^e)
it‘s just lns and lnk, but you Switch the k to lns, so lnsk = ln
Yes
Hmm
I guess somewhere between 1 and e, but more near to 1 than e
lns1(e^e) = 2, lns0(e^e) = e^e, hmm
Hmm, i think not, because for 1 it‘s already 2 and that’s to small
Yeah, but 0 is e^e,
I see
Yeah
1/2?
Hmm
I think not because it‘s stronger than exponetial growth, but it’s possible
Is there a formula for lnsk ?
Or something where you can use lns to calculate its k
RoyalBanana
Eg, ${}^{(ln^s(x)-k)}e=ln_k(x)$
RoyalBanana
Hmm, there must be something that does n-1
Maybe this
Yeah I was thinking about something with that
So we can generalize this
$H_{-k}(n,a,b))=log^n_{a,k}(b)$
RoyalBanana
$H_{k}(n,a,b)=log^n_{a,-k}(b)$
RoyalBanana
I wonder if we can combine these two formulas then
$H(n,a,b)=log^n_{a,-1}(b)$
RoyalBanana
$H(n,a,b-k)=log^n_{a,-1}(b-k)$
RoyalBanana
$H_{k}(n-1,a,c)=log^{n-1}_{a,-k}(c)$
RoyalBanana
Ok
Now to plug everything in
$H(n,a,b)=H_k(n-1,a,H(n,a,b-k))$
$log^n_{a,-1}(b)=log^{n-1}{a,-k}(log^n{a,-1}(b-k))$
RoyalBanana
RoyalBanana
Interesting
Yeah
Reminds me of this fact $log_a^n(log_{a,k}^{n-1}(x))=log_a^n(x)-k$
RoyalBanana
Yup, cancels when 0
I wonder if this works for other numbers not just -1
Lemme test this
But you can‘t change n-1 i think
Ok so with base e for simplicity the formula above is
$ln^n_{-1}(b)=ln^{n-1}{k}(ln^n{-1}(b+k))$
RoyalBanana
So: for example $ln^n_{2}(b)=ln^{n-1}{k}(ln^n{2}(b+k))?$
RoyalBanana
RoyalBanana
RoyalBanana
$ln_{2}(b)=e^{(-k)}*ln_2(b+k)?$
RoyalBanana
Oooh ok well after looking at graphs this seems to work only with -1 and 1
So if it's one it's $log^n_a(b)=log^{n-1}_{a,k}(log^n_a(b+k))$
RoyalBanana
Interesting
So $log_a^n(log_{a,k}^{n-1}(x))=log_a^n(x)-k$
and $log^n_a(b)=log^{n-1}_{a,k}(log^n_a(b+k))$
RoyalBanana
You could probably use this to find log^(n-1)!
Anyway soo using that $ln^s(b)=ln_{k}(ln^s(b+k))$
RoyalBanana
Wait is that really true?
that would be cool
So then $ln^s(b+1)=e^{ln^s(b)}?$
I feel like that's too good to be true
Ah I only checked if it worked for 1 for n=3 ofc
Ok ignore this this is wrong
So this only works with -1
Wish I could pin things lol
Soo for example
${}^ba=log_{a,k}({}^{(b+k)}a)$
RoyalBanana
makes sense
Whoa
That's incorrect
Hmm
I trying to find something for this one formula with lns and ln^n
1
e
e^^(e-1)
e^^e * e^-1 - 1
This is all I got for the 4 n
I can’t See a pattern that can be generalized
And how could we compute such Numbers
Hmm
I think I could continue with this
And then find out the optimal value
And solve for 1
Uh I mean y
I just need to replace Capital Pi with some non integer thingy
If n is unchanging btw it's literally just some constant to the power of x
so if we ignore x for now, we can extend this formula to non integers to figure it out f(n)=f(n-1)ln(f(n-1))
(Once we figure out what f(n) is here, f(x,n)=f(n)^x)
Interesting
and f(1)=2
Yeah true
I think it‘s just f(x) = e(x)^W(1). e(0)^W(1) = 1, e(1)^W(1) = e^W(1), e(2)^W(1) = e^W(e^W(1)),…
But we can‘t just do that if we want to take the nth derivative again
And btw e(infinity)^W(1) = e
But I want to have the General Function of that so I Can take the derivative, and after undestanding the pattern the nth derivative and then Talking the nth derivative n times
Ye we proved that already lol
can you not use that notation though it's easily confused
Umm $e^{W(1)} \ne 2$
RoyalBanana
Ooh.. f(x-1)=e^W(f(x))
I see what you're going for
Wait it reaches a stable value at an infinity
we can use the extension thing
hold on
https://youtu.be/9p_U_o1pMKo?si=bi5XVCDyaHNhHdz5
The same one used here
The harmonic numbers are the partial sums of the harmonic series - sums of whole number reciprocals. This video explores how we can extend their domain to the entire real line.
The animations for this video were made with the community edition of Manim (https://www.manim.community). Huge thanks to everyone who worked on the library, as well as ...
$\lim_{N \to -\infty} f(N+x)-f(N)=0$
RoyalBanana
$f(x+1)=f(x)ln(f(x))$
$f(x-1)=e^{W(f(x))}$
RoyalBanana
s=e^W(e^W(e^W(...
e^W(s)=s
W(s)e^W(s)=W(s)s
s=W(s)s
s=0, or W(s)=1
s=0, or s=e
clearly not 0 so s=e
so we need a super recursive formula
$f(x+2)=f(x+1)\ln(f(x+1))=f(x)\ln(f(x))\ln(f(x)\ln(f(x)))$
RoyalBanana
ah wait
I can reuse the thing from before
$f(x+n)=f(x)\prod_{m=1}^{n}(\sum_{k=1}^{m}ln_k(f(x)))$
RoyalBanana
Nice
$\lim_{N \to -\infty} f(x+N)-f(N)=0$
RoyalBanana
$f(x+N)=f(x)\prod_{m=1}^{N}(\sum_{k=1}^{m}ln_k(f(x)))$
RoyalBanana
hmm imma use like $\omega(x,n)$
RoyalBanana
RoyalBanana
Wo you mean x * ln(x) = 1?
Uhhhhh
Mine too if I try to understand this haha
Oh wait, now I understand, it aproaches e for infinity
Like √2 ^^ infinity approches 2
So this only works for sums specifically but there's some way to generalize this for other things I suppose
like f(x+1)=g(f(x))
Oh okay, I see
And we need to find at which Point of the nth root of y^x (y is just a constant, for example 2) repeated n times the function crosses 1 to find a new constant
I don‘t know
It‘s probably something with lnk, because it’s repeated ln
But how to take the derivative of a recrusive function?
It's always something to do with f(x+N) and f(N)
Youd have to find the extension first
Maybe just take the natrual log of it and multiply it to it‘s normal form
I can say though with confidence that $f'(-\infty)=0$
RoyalBanana
Like with this
Yeah probably
The extension we're doing relies on the fact that it smooths out which the derivative being 0 means the same thing
What would be the inverse of e^W(x) ??
xlnx
Yeah
^
Isn‘t ln(x) just the inverse of e^x ?
you can see bc $e^{W(x)}*ln(e^{W(x)})=W(x)e^{W(x)}=x$
RoyalBanana
True True
I suppose this means btw that W(xlnx)=lnx
Since xlnx is the inverse of e^W(x) that means e^W(xlnx)=x
so W(xlnx)=lnx
I'm workin on this
this is interesting
It seems to have to do with the inverse of g
Sorry for my handwriting, but I think I found something
Wait how'd you get ln(4)^^2?
ln(4) * ln(ln(4)) = ln(ln(4)^ln(4))
This is just really useful in other recursive applications too so imma continue on this
I wish I had paper rn but I'm not at my house
I have to write with the latex bot and desmos lol
Oh Nicee. Yeah looks very cool.
Nice lol
I think I’ll watch the Video, I haven‘t watched it yet
Hmm yeahh
I think the other things get complicated very quickly
I'll figure it out lol
Oh it's pretty useful
Very interesting video, very nice
Yeah lol
Also their video on factorials is a continuation on that
anyway that's where I got this from
Nicee. Factorials are maybe found with the capital Pi thingy
Nice
I tried it with that one Method but it didn‘t work very well
Hmm, maybe something Like this
I understand it now
How?
Hmm
$f(x)=f(0)+\sum_{n=1}^{\infty}(g(x+n)-g(n))$
RoyalBanana
This is for which function?
and all that's left is f(0)+g(1)+g(2)+...+g(x-1)
If f(x+1)=f(x)+g(x+1)
Uhh, Lemme think
What is f(0) ?
f(0)
Okay
anything it works for any function with this property
I might've made a typo here, but it's something like this
$f(1)=f(0)+g(2)-g(1)+g(3)-g(2)+g(4)-g(3)...$
RoyalBanana
ah I did make a typo
x = 1, f(0) + g(2) -g(1) + g(3) - g(2)…, ah, f(0) -g(1) + g(3)
$f(x)=f(0)+\sum_{n=1}^{\infty}(g(n)-g(n+x))$
RoyalBanana
Nicee
You see they cancel
I fixed the typo
Yeah
anyway this only works if it flattens out in the limit bc there is technically like two extra terms left at the end
Hmm
if $\lim_{N \to \infty} f(N+n)-f(N)=0$ it works
Intresting
RoyalBanana
for some integer n
Yeah
this is the same as saying it flattens out
This canceling thing though, can surely be used for more than just sums
$\sum_{n=1}^{x}g(n)=\sum_{n=1}^{\infty}(g(n)-g(n+x))$
RoyalBanana
Uh, but it would need to be something like a * b = 1
But that’s cool
Exponetiation wouldn‘t work i guess, because of the commutative rule
Slow down lol we'll figure it out for the more general case f(x+1)=g(f(x)) lol
I'm just seeing multiple examples to see if I can notice a pattern
hmm let's do f(x+1)=f(x)g(x+1)
So $f(x)=f(0)\prod_{n=1}^{x}g(n)$
RoyalBanana
So.. the reason this works is bc it cancels out
$\prod_{n=1}^{x}g(n)=\prod_{n=1}^{\infty}\frac{g(n)}{g(n+x)}?$
RoyalBanana
f(x) = f(x-1) * ln(f(x-1))
Looks very simple
Thats for the nth derivative thingy
This could work
Or Just f(x) = ln(f(x-1)^^2)
The g(x) still depends on f though so we don't know what g(x) is at non integer values of x
Ohh I see it has the same problem of the extra values at high n
uh
wrong trick
it's the reverse
the product of ln doesn't turn into anything
ln of a product does
unfortunately
Lemme write out the terms
$g(1)=\frac{g(1)}{g(2)}\frac{g(2)}{g(3)}\frac{g(3)}{g(4)}...?$
RoyalBanana
ahh it has an extra /g(N)
So $\prod_{n=1}^{x}g(n)=\lim_{N \to \infty} g(N)\prod_{n=1}^{N}\frac{g(n)}{g(n+x)}$
RoyalBanana
Uhh, i don‘t get it
$\ln(\prod)=\sum \ln$
RoyalBanana
Yeah but I didn’t take the ln of the product, I just simplified the equation and then just used the sum thingy to make it more compact
Am confused
?
What ln trick?
Ohhh I see you took the ln of both sides ofc
yeah sure that works
Ah lemme check it for x=2
$g(1)g(2)=g(6)\frac{g(1)}{g(3)}\frac{g(2)}{g(4)}\frac{g(3)}{g(5)}\frac{g(4)}{g(6)}?$
RoyalBanana
Yeah
so it's $\prod_{n=0}^{x-1}g(N+n)$ not $g(N)$
RoyalBanana
Math is complicated. My Brain is burining rn. I never used the sum and capital pi in my life before
ahhh but the requirement for the formula was $\lim_{N \to \infty} g(N+n)=g(N)$
RoyalBanana
So we can just say g(N)^x !
Fair lol
remember to take breaks lol
Ahh so this is how we get rid of the x being a non integer problem, using the fact that the limit is equal!
So finally $\prod_{n=1}^{x}g(n)=\lim_{N \to \infty} g(N)^x\prod_{n=1}^{N}\frac{g(n)}{g(n+x)}$
RoyalBanana
Nicee
Yeah, maybe
RoyalBanana
Hmm
Ok but we gotta solve the general case first ofc
so far we got it for sums and products
I think I have an idea. Couldn‘t we use this to Break down tetration into smauler operations and then extend it to the reals?
These are clues that definitely help
Yeah I just learned how to use them effectively
lol
ln2(a^^b) = ln(a^^b) + ln2(a) I guess
$f(x+1)=g(f(x))$ I mean
RoyalBanana
that would instantly solve our f(x+1)=f(x)ln(f(x)) thingy
I’m just to stupid to understand it right now, I can’t help you a lot rn
This would be crazy
hey you're not stupid it's complicated even for me lol
Ah okayy haha lol
I just need a little bit more time to wrap my mind around it
Yeah it's crazy lol
Ah, I mean ln2(a^^b) = ln(a^^b-1) + ln2(a)
the examples help me wrap my mind around it though lol
yep!
Because ln(a^^b) = a^^(b-1) * ln(a)
b-1
Same
Useful
Imma try $f(x+1)=f(x)^{g(x+1)}$ now
Hmm
RoyalBanana
Oh I understand
So it cancels for the product bc division is the inverse of multiplication
It cancels for the sum bc subtraction is the inverse of adding
soo.. the inverse of exponentiation is log or roots
I think it's roots here bc g is the exponent
Hmm
Need some notation for this
oh yeah $(x^a)^b=x^{ab}$
RoyalBanana
Can use that for now
just to make it easier to write
I'm doing this on desmos and I gotta say I think I'm making progress
good progress!
Uhh, looks Crazy
True, but you're just not used to the capital pi notation yet
I somewhat understand this
Yeah I know
I‘ll get used to it in some time
I‘ll just solve some Problems with it
One of them is my beloved f(x) = f(x-1) * ln(f(x-1))
yep
I'm cooking
Nicee
I think I'm onto something here..
I made this thing F, in this case $F(f,x)=f^{g(x)}$
because $f(x+1)=f(x)^{g(x)}$
RoyalBanana
RoyalBanana
by definition
Let's define $F^{-1}$, in this case $F^{-1}(f,x)=f^{\frac{1}{g(x)}}$
RoyalBanana
$F(F^{-1}(f,x),x)=f$
RoyalBanana
RoyalBanana
Finally something: f(x+k) = f(x) * k! * capitalPi(m)(lnm(x))
Uh
Ah I See recrusive F
Wait I think this is actually True because it‘s ln, ln(f(x)) = ln(f(x-1)) + ln(ln(f(x-1))), so this is addition and this would make Perfect sense for the factorial
The only Problem now is the capital pi which is only of integers
Hmm, could we extend the lnk function to the reals?
ye
sure why not
I'm almost done with the extension thing btw
soon
soon you'll be able to solve $f(x+1)=g(f(x))$ I think for any g(x)
RoyalBanana
*as long as f(x) flattens out
the limit definition
uhh
As long as $\lim_{N \to \infty} f(N+1)-f(N)=0$
RoyalBanana
Oh interesting
so this isn't true for tetration
but!
so normal teteration is for example
f(x+1)=e^f(x)
that doesn't meet that limit requirement
but we can do a little trick
f(x+1)=1/e^(1/f(x))
that is equal to 1/the tetration function
This is true for 1/tetration function ofc bc the tetration function grows exponentiatially large so 1/it grows less and less
interesting
so we can find the extension of 1/it then do 1/that which cancels out to just give the extension of the tetration function!
Ok more similar notation lol (dw won't be needed for long) $F_n(f,x)=F(F(F...(F(f,x+1),x+2),x+3...,x+n)$
RoyalBanana
I'm using it for the general case lol
this is kinda interesting how it works lol
RoyalBanana
RoyalBanana
Hmm
Oh wait $F_N(f(0),0)=F_{N-1}(f(1),1)=F_{N-2}(f(2),2)=...=f(N)$
RoyalBanana
So $F^{x}(F^{-1}_N(f(N),x),N)$
RoyalBanana
I think that's as far as simplifying goes
Oh I didn't mention $F^{n}$ is like $F_{n}$ except the terms on the right don't go up they stay the same there's just n terms
RoyalBanana
Let's test this now
$F(f,x)=f^{g(x)}$ because $f(x+1)=f(x)^{g(x)}$
and in this case $F^{-1}(f,x)=f^{\frac{1}{g(x)}}$
RoyalBanana
$F_N^{-1}(f,x)=?$
RoyalBanana
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RoyalBanana
$F^{n-1}(a^{g(b)},b)$
RoyalBanana
$F^{n-2}(({a^{g(b)})}^{g(b)},b)$
RoyalBanana
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RoyalBanana
ok
there
so this should work
in theory
wait what was f(N)?
ah yes
$f(0)^{\prod_{n=1}^{N}g(n)}$
RoyalBanana
So we can plug that in here..
If $f(x+1)=f(x)^{g(x)}$ and f flattens out as x gets bigger, then
$ f(x)= \lim_{N \to \infty}f(N)^{{g(N)}^x\prod_{n=1}^{N}\frac{g(n)}{g(x+n)}}$
RoyalBanana
My brains fried
Ah I made a typo f(0) not f(N) lol
I do not understand haha
that's ok
but the important part is it works lol
fair lol
anyway I just realized that specific way doesn't work anyway
for $f(x+1)=g(f(x))$ you would need to know $g_n(f(0))$ for non whole n which obviously if you knew that then you wouldn't need this method lol
RoyalBanana
I'm gonna try something else idk
RoyalBanana
hmm
I have an idea
so basically g "steps" 1 to the right on the graph
g_n "steps" n to the right
hmm
Two steps of 1/2 is the same as a step of 1
$g_{\frac{1}{2}}(g_{\frac{1}{2}}(x))=g(x)$
RoyalBanana
so we need a function that satisfies f(f(x))=g(x)
I wonder if this has just one solution or multiple solutions
I was Messing around with my recrusive function f(x) = f(x-1) * ln(f(x-1) and through I rerange some stuff to get f(x) = e^(f(x-1)) + f(x-1), this function is grows very strong for positive values, but is very stable for negative values. Maybe I could use something with x aproaches negative infinity
Idk
Hmm, not sure
I think it should have multiple
I was thinking
about the solution in that video
if you get just one segment 1 long then it solves the whole function
So if the function flattens out then we can get that segment
that's the idea
normally though they get it by doing some other method that doesn't work here but I think I have an idea
Can you show the steps you did to get that?
Yeah true
Nvm my shuffeling around with my function isn‘t true sadly, I forgot the ln(f(x)), instead of the f(x)
I was interested in the stuff of the video and I was thinking about solving f(x) = x^f(x-1), which is the same like the sum and factorial, but with exponetiation. During the process of solving it, I found it’s pretty much iterated logarithms
This would solve so much: lnk(x) = ln(lnk-1(x))
Maybe there could be some other capital letter for exponetiation, the only problem is that it’s not commutative
RoyalBanana
For any x
Yeah
so that ofc means $\lim_{N \to \infty} f'(N)=0$
RoyalBanana
Only if it flatterns out
I'm pretty sure that also means though $\lim_{N \to \infty} f''(N)=0$
RoyalBanana
If it flattens out
Hmm
I'm pretty sure that also also means though $\lim_{N \to \infty} f'''(N)=0$
RoyalBanana
Derivative?
If the derivative of the function is going to 0
that means the derivative of the derivative is also going to 0
etc
so all of the derivatives are 0
So $\lim_{N \to \infty} f^{(n)}(N)=0$ for any n
RoyalBanana
Now
Yess
We can get f'(x-1) if you take the derivative of both sides of the recursive formula and rearrange a bit
so we can get f'(x-n) for some whole integer n
meaning we can take some huge number N, estimate the derivative there and backtrack, finding all of the derivatives before it with this
So we can take the limit as N goes to infinity and the estimation of the derivative will get better so the derivatives will get better and eventually they should be exactly right
so we can figure out the all the derivatives of the points
right?
now there's no reason we can't do that again and get a formula for f''(x-n)
so we can do that again
get the 2nd derivative of all the points
etc
we can get every derivative
Taylor series!
lol it would be very complicated though
but I think it'd work
Hmm
Sounds interesting, I just don‘t completely understand it yet
Taylor series is something with iterative derivative i guess
With taylor series you just need all the derivatives of a function at one point
and that's all
Ah okay
Sounds cool
And you just take the sum of all These derivatives?
Ah I See where you‘re going with this
Isn‘t there something with the factorial?
Hmm, taylor Series with the tetration Sounds interesting to me