How Does Exponentiation with Complex Variables Influence Vector Orientation?

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Homework Help Overview

The discussion revolves around the influence of exponentiation with complex variables on vector orientation, particularly focusing on the mathematical properties and implications of raising complex vectors to powers. The original poster introduces an equation involving complex vectors and their powers, referencing trigonometric identities and rotation in the complex plane.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants explore the relationship between complex exponentiation and vector orientation, with some questioning the assumptions made about parallelism and the conditions under which the original poster's equation holds. There are references to De Moivre's formula and discussions about the implications of using ArcTan in the context of complex exponentiation.

Discussion Status

The discussion is ongoing, with participants providing insights and raising questions about the definitions and conditions related to the original poster's equation. Some participants are clarifying concepts while others are exploring different interpretations of the relationships between the vectors involved.

Contextual Notes

There are mentions of potential ambiguities regarding the use of ArcTan and its multiple values, as well as the conditions under which the exponentiation is defined. The discussion highlights the need for clarity on the assumptions made about the relationships between the complex numbers and their powers.

Miike012
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I've been reading a book on complex variables and I came up with an equation which may or may not be useful but I thought it was interesting

Explanation
Given a complex vector z = a + bi I can calculate z raised to the M + 1 power where M = 360/ArcTan(b/a)

Side Note
Sorry I didn't give any reason to the alterations to the equations below but basically the logic behind the reason is that say z = |z|(cos(θ) + isin(θ)) then I know that zn = |z|n(cos(nθ) + isin(nθ)) and because I know trig functions repeat I know that the product will eventually rotate 360 degrees measured from vector z.

For example given z = |z|(cos(θ) + isin(θ)) and say zm = |z|m(cos(θ+ 2∏) + isin(θ+2∏)
therefore z and zm are parallel and differ by some scalar

Equation
zM+1 = [|z|M+1/|Z|M+1]zM+1 = [|z|M+1/|z|]z =[|z|M]z


zM+1 =[|z|M]z
It seems to only work when it has rotated around once but I can change that
 
Last edited:
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For Example

(101+17i)360/ArcTan(17/101) + 1 = (101 + 17i)*√(101^2+17^2)360/ArcTan(17/101)

Notice that the left side is raised to a power greater than 1 while the right side is raised to the first power then multiplied by some constant
 
I wasn't implying you came up with it yourself, I was just suggesting something along the lines of what I thought you were doing. Is your exponentiation defined only for that specific value with ArcTan? And is that ArcTan a value in [0,2pi) ( since ArcTan is multiple-valued)?

I don't know if I understood correctly, but z and z^n are not always parallel; just take

z=x+ix ; then z^2=i2x , which is not parallel to x+ix.
 
Last edited:
Bacle2 said:
I wasn't implying you came up with it yourself, I was just suggesting something along the lines of what I thought you were doing. Is your exponentiation defined only for that specific value with ArcTan? And is that ArcTan a value in [0,2pi) ( since ArcTan is multiple-valued)?

I don't know if I understood correctly, but z and z^n are not always parallel; just take

z=x+ix ; then z^2=i2x , which is not parallel to x+ix.
if zn = zM+1 where M = 360/45 then zn is parallel to z where z = (x + ix)
 

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