Solve $i^i^i^ldots$ [duplicate]
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What is the value of $i^i^i^ldots$? [closed]
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How to find $$i^i^i^ldots quad :quad i=sqrt-1$$
I'm able to find the solution for the finite powers
using
$$i=e^i(2kpi+fracpi2)quad:quad kinmathbbZ$$
$$i^i=e^-(2kpi+fracpi2)$$
$$i^i^i=e^-i(2pi k+fracpi2)=-i$$
$$i^i^i^i=e^(2pi k+fracpi2) $$
$$textand so on$$
but what should be the approach to solve for infitie powers$space$?
complex-numbers exponentiation tetration power-towers
marked as duplicate by Math Lover, Simply Beautiful Art, lab bhattacharjee, Did, StubbornAtom Aug 12 at 4:33
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |Â
up vote
2
down vote
favorite
This question already has an answer here:
What is the value of $i^i^i^ldots$? [closed]
1 answer
How to find $$i^i^i^ldots quad :quad i=sqrt-1$$
I'm able to find the solution for the finite powers
using
$$i=e^i(2kpi+fracpi2)quad:quad kinmathbbZ$$
$$i^i=e^-(2kpi+fracpi2)$$
$$i^i^i=e^-i(2pi k+fracpi2)=-i$$
$$i^i^i^i=e^(2pi k+fracpi2) $$
$$textand so on$$
but what should be the approach to solve for infitie powers$space$?
complex-numbers exponentiation tetration power-towers
marked as duplicate by Math Lover, Simply Beautiful Art, lab bhattacharjee, Did, StubbornAtom Aug 12 at 4:33
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
2
Note that one should define exponentiation to be single-valued by choosing a branch, which would make this question clearer...
â Simply Beautiful Art
Aug 12 at 3:03
2
Your method of computing the iterates is not correct. Note that $(i^i)^i ne i^(i^i)$.
â Shalop
Aug 12 at 3:18
@Shalop What should be the correct method of computing the iterates?
â Arpit Yadav
Aug 12 at 3:21
1
Going by your rules, we say $i^z = e^big(2k+frac12big)ipi z$. Let us call this function $f(z)$. Now compute $f(i)$. Then compute $f(f(i))$. Then compute $f(f(f(i)))$. You will see that it is not the same as what you are doing.
â Shalop
Aug 12 at 3:44
1
See also: What is the order when doing $x^y^z$ and why?.
â Simply Beautiful Art
Aug 12 at 4:04
add a comment |Â
up vote
2
down vote
favorite
up vote
2
down vote
favorite
This question already has an answer here:
What is the value of $i^i^i^ldots$? [closed]
1 answer
How to find $$i^i^i^ldots quad :quad i=sqrt-1$$
I'm able to find the solution for the finite powers
using
$$i=e^i(2kpi+fracpi2)quad:quad kinmathbbZ$$
$$i^i=e^-(2kpi+fracpi2)$$
$$i^i^i=e^-i(2pi k+fracpi2)=-i$$
$$i^i^i^i=e^(2pi k+fracpi2) $$
$$textand so on$$
but what should be the approach to solve for infitie powers$space$?
complex-numbers exponentiation tetration power-towers
This question already has an answer here:
What is the value of $i^i^i^ldots$? [closed]
1 answer
How to find $$i^i^i^ldots quad :quad i=sqrt-1$$
I'm able to find the solution for the finite powers
using
$$i=e^i(2kpi+fracpi2)quad:quad kinmathbbZ$$
$$i^i=e^-(2kpi+fracpi2)$$
$$i^i^i=e^-i(2pi k+fracpi2)=-i$$
$$i^i^i^i=e^(2pi k+fracpi2) $$
$$textand so on$$
but what should be the approach to solve for infitie powers$space$?
This question already has an answer here:
What is the value of $i^i^i^ldots$? [closed]
1 answer
complex-numbers exponentiation tetration power-towers
edited Aug 12 at 3:07
Simply Beautiful Art
49.4k572172
49.4k572172
asked Aug 12 at 1:02
Arpit Yadav
331215
331215
marked as duplicate by Math Lover, Simply Beautiful Art, lab bhattacharjee, Did, StubbornAtom Aug 12 at 4:33
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
marked as duplicate by Math Lover, Simply Beautiful Art, lab bhattacharjee, Did, StubbornAtom Aug 12 at 4:33
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
2
Note that one should define exponentiation to be single-valued by choosing a branch, which would make this question clearer...
â Simply Beautiful Art
Aug 12 at 3:03
2
Your method of computing the iterates is not correct. Note that $(i^i)^i ne i^(i^i)$.
â Shalop
Aug 12 at 3:18
@Shalop What should be the correct method of computing the iterates?
â Arpit Yadav
Aug 12 at 3:21
1
Going by your rules, we say $i^z = e^big(2k+frac12big)ipi z$. Let us call this function $f(z)$. Now compute $f(i)$. Then compute $f(f(i))$. Then compute $f(f(f(i)))$. You will see that it is not the same as what you are doing.
â Shalop
Aug 12 at 3:44
1
See also: What is the order when doing $x^y^z$ and why?.
â Simply Beautiful Art
Aug 12 at 4:04
add a comment |Â
2
Note that one should define exponentiation to be single-valued by choosing a branch, which would make this question clearer...
â Simply Beautiful Art
Aug 12 at 3:03
2
Your method of computing the iterates is not correct. Note that $(i^i)^i ne i^(i^i)$.
â Shalop
Aug 12 at 3:18
@Shalop What should be the correct method of computing the iterates?
â Arpit Yadav
Aug 12 at 3:21
1
Going by your rules, we say $i^z = e^big(2k+frac12big)ipi z$. Let us call this function $f(z)$. Now compute $f(i)$. Then compute $f(f(i))$. Then compute $f(f(f(i)))$. You will see that it is not the same as what you are doing.
â Shalop
Aug 12 at 3:44
1
See also: What is the order when doing $x^y^z$ and why?.
â Simply Beautiful Art
Aug 12 at 4:04
2
2
Note that one should define exponentiation to be single-valued by choosing a branch, which would make this question clearer...
â Simply Beautiful Art
Aug 12 at 3:03
Note that one should define exponentiation to be single-valued by choosing a branch, which would make this question clearer...
â Simply Beautiful Art
Aug 12 at 3:03
2
2
Your method of computing the iterates is not correct. Note that $(i^i)^i ne i^(i^i)$.
â Shalop
Aug 12 at 3:18
Your method of computing the iterates is not correct. Note that $(i^i)^i ne i^(i^i)$.
â Shalop
Aug 12 at 3:18
@Shalop What should be the correct method of computing the iterates?
â Arpit Yadav
Aug 12 at 3:21
@Shalop What should be the correct method of computing the iterates?
â Arpit Yadav
Aug 12 at 3:21
1
1
Going by your rules, we say $i^z = e^big(2k+frac12big)ipi z$. Let us call this function $f(z)$. Now compute $f(i)$. Then compute $f(f(i))$. Then compute $f(f(f(i)))$. You will see that it is not the same as what you are doing.
â Shalop
Aug 12 at 3:44
Going by your rules, we say $i^z = e^big(2k+frac12big)ipi z$. Let us call this function $f(z)$. Now compute $f(i)$. Then compute $f(f(i))$. Then compute $f(f(f(i)))$. You will see that it is not the same as what you are doing.
â Shalop
Aug 12 at 3:44
1
1
See also: What is the order when doing $x^y^z$ and why?.
â Simply Beautiful Art
Aug 12 at 4:04
See also: What is the order when doing $x^y^z$ and why?.
â Simply Beautiful Art
Aug 12 at 4:04
add a comment |Â
1 Answer
1
active
oldest
votes
up vote
3
down vote
accepted
$X = i^i^i^cdot$
So $X = i^X$.
So $log (X) = X log (i)$.
So $log (X) over X = log (i)$.
So $X = i W(-i)$, where $W$ is the Lambert $W$ or PolyLog function.
Mathematica evaluates this to $X = 0.44 + 0.36 i$.
Here's a graph on the imaginary plane of 200 successive exponentiations with the solution as a red dot:
4
This is a fixed point but proving that it converges is more work.
â parsiad
Aug 12 at 1:18
4
@parsiad. Fair enough. Good thing the OP didn't ask for a proof of convergence!
â David G. Stork
Aug 12 at 1:19
1
@DavidG.Stork Does series converge to any particular value?
â Arpit Yadav
Aug 12 at 1:21
This is purely formal, obviously.
â Did
Aug 12 at 3:51
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
3
down vote
accepted
$X = i^i^i^cdot$
So $X = i^X$.
So $log (X) = X log (i)$.
So $log (X) over X = log (i)$.
So $X = i W(-i)$, where $W$ is the Lambert $W$ or PolyLog function.
Mathematica evaluates this to $X = 0.44 + 0.36 i$.
Here's a graph on the imaginary plane of 200 successive exponentiations with the solution as a red dot:
4
This is a fixed point but proving that it converges is more work.
â parsiad
Aug 12 at 1:18
4
@parsiad. Fair enough. Good thing the OP didn't ask for a proof of convergence!
â David G. Stork
Aug 12 at 1:19
1
@DavidG.Stork Does series converge to any particular value?
â Arpit Yadav
Aug 12 at 1:21
This is purely formal, obviously.
â Did
Aug 12 at 3:51
add a comment |Â
up vote
3
down vote
accepted
$X = i^i^i^cdot$
So $X = i^X$.
So $log (X) = X log (i)$.
So $log (X) over X = log (i)$.
So $X = i W(-i)$, where $W$ is the Lambert $W$ or PolyLog function.
Mathematica evaluates this to $X = 0.44 + 0.36 i$.
Here's a graph on the imaginary plane of 200 successive exponentiations with the solution as a red dot:
4
This is a fixed point but proving that it converges is more work.
â parsiad
Aug 12 at 1:18
4
@parsiad. Fair enough. Good thing the OP didn't ask for a proof of convergence!
â David G. Stork
Aug 12 at 1:19
1
@DavidG.Stork Does series converge to any particular value?
â Arpit Yadav
Aug 12 at 1:21
This is purely formal, obviously.
â Did
Aug 12 at 3:51
add a comment |Â
up vote
3
down vote
accepted
up vote
3
down vote
accepted
$X = i^i^i^cdot$
So $X = i^X$.
So $log (X) = X log (i)$.
So $log (X) over X = log (i)$.
So $X = i W(-i)$, where $W$ is the Lambert $W$ or PolyLog function.
Mathematica evaluates this to $X = 0.44 + 0.36 i$.
Here's a graph on the imaginary plane of 200 successive exponentiations with the solution as a red dot:
$X = i^i^i^cdot$
So $X = i^X$.
So $log (X) = X log (i)$.
So $log (X) over X = log (i)$.
So $X = i W(-i)$, where $W$ is the Lambert $W$ or PolyLog function.
Mathematica evaluates this to $X = 0.44 + 0.36 i$.
Here's a graph on the imaginary plane of 200 successive exponentiations with the solution as a red dot:
edited Aug 12 at 1:49
answered Aug 12 at 1:16
David G. Stork
8,05521131
8,05521131
4
This is a fixed point but proving that it converges is more work.
â parsiad
Aug 12 at 1:18
4
@parsiad. Fair enough. Good thing the OP didn't ask for a proof of convergence!
â David G. Stork
Aug 12 at 1:19
1
@DavidG.Stork Does series converge to any particular value?
â Arpit Yadav
Aug 12 at 1:21
This is purely formal, obviously.
â Did
Aug 12 at 3:51
add a comment |Â
4
This is a fixed point but proving that it converges is more work.
â parsiad
Aug 12 at 1:18
4
@parsiad. Fair enough. Good thing the OP didn't ask for a proof of convergence!
â David G. Stork
Aug 12 at 1:19
1
@DavidG.Stork Does series converge to any particular value?
â Arpit Yadav
Aug 12 at 1:21
This is purely formal, obviously.
â Did
Aug 12 at 3:51
4
4
This is a fixed point but proving that it converges is more work.
â parsiad
Aug 12 at 1:18
This is a fixed point but proving that it converges is more work.
â parsiad
Aug 12 at 1:18
4
4
@parsiad. Fair enough. Good thing the OP didn't ask for a proof of convergence!
â David G. Stork
Aug 12 at 1:19
@parsiad. Fair enough. Good thing the OP didn't ask for a proof of convergence!
â David G. Stork
Aug 12 at 1:19
1
1
@DavidG.Stork Does series converge to any particular value?
â Arpit Yadav
Aug 12 at 1:21
@DavidG.Stork Does series converge to any particular value?
â Arpit Yadav
Aug 12 at 1:21
This is purely formal, obviously.
â Did
Aug 12 at 3:51
This is purely formal, obviously.
â Did
Aug 12 at 3:51
add a comment |Â
2
Note that one should define exponentiation to be single-valued by choosing a branch, which would make this question clearer...
â Simply Beautiful Art
Aug 12 at 3:03
2
Your method of computing the iterates is not correct. Note that $(i^i)^i ne i^(i^i)$.
â Shalop
Aug 12 at 3:18
@Shalop What should be the correct method of computing the iterates?
â Arpit Yadav
Aug 12 at 3:21
1
Going by your rules, we say $i^z = e^big(2k+frac12big)ipi z$. Let us call this function $f(z)$. Now compute $f(i)$. Then compute $f(f(i))$. Then compute $f(f(f(i)))$. You will see that it is not the same as what you are doing.
â Shalop
Aug 12 at 3:44
1
See also: What is the order when doing $x^y^z$ and why?.
â Simply Beautiful Art
Aug 12 at 4:04