CONCLUSION 1 : conditions for nice tetration : second derivative !!
#3
Ok this idea does have issues and I guess I should adress them.

If you take the product formula for the derivative of tet(x) a bit too far , although that has logical justifications (!) , we run into this

tet(-1) = 0

tet(0) = 1

tet ' (0) = tet(0) * tet ' (-1).

But tet(0) = 1 , so

tet ' (0) = 1 * tet ' (-1) = tet ' (-1)

Since tet ' (0) = tet ' (-1) this means the function cannot be convex in [-1,0].

SO sufficiently-differentiable solutions must have an inflection point in [-1,0] !!


This means our unique zero of the second derivative is not so unique afterall.


Or maybe we should set

sexp ' ' ( - 1/2) = 0

to make the Riemann fans happy Smile

I have to think about these issues.

Although these issues are very old ofcourse.

My apologies if I made things sound " completed " , they are not.

However  the remark about the theta function theta(x) has analogues here !

So theta(x) is not so free to choose as you might have believed !


regards

tommy1729
Reply


Messages In This Thread
RE: CONCLUSION 1 : conditions for nice tetration : second derivative !! - by tommy1729 - 02/22/2023, 11:44 PM

Possibly Related Threads…
Thread Author Replies Views Last Post
Question Derivative of the Tetration Logarithm Catullus 1 3,434 07/03/2022, 07:23 AM
Last Post: JmsNxn
  On the first derivative of the n-th tetration of f(x) Luknik 5 9,178 10/28/2021, 11:53 AM
Last Post: tommy1729
  Semi-exp and the geometric derivative. A criterion. tommy1729 0 5,810 09/19/2017, 09:45 PM
Last Post: tommy1729
  How to find the first negative derivative ? tommy1729 0 5,746 02/13/2017, 01:30 PM
Last Post: tommy1729
  A calculus proposition about sum and derivative tommy1729 1 7,645 08/19/2016, 12:24 PM
Last Post: tommy1729
  Derivative of exp^[1/2] at the fixed point? sheldonison 10 37,782 01/01/2016, 03:58 PM
Last Post: sheldonison
  Derivative of E tetra x Forehead 7 27,826 12/25/2015, 03:59 AM
Last Post: andydude
  A derivative conjecture matrix 3 14,252 10/25/2013, 11:33 PM
Last Post: tommy1729
  tommy's uniqueness conditions tommy1729 5 19,407 07/19/2010, 05:47 AM
Last Post: bo198214
  Actual formulas for tetration and its derivative hyper4geek 14 56,973 08/31/2007, 11:29 PM
Last Post: jaydfox



Users browsing this thread: 1 Guest(s)