What are the solutions for e^z = 1 and e^z = 1 + i?

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Discussion Overview

The discussion revolves around finding solutions to the equations e^z = 1 and e^z = 1 + i within the context of complex analysis. Participants explore various approaches and methods to solve these equations, including polar forms and trigonometric identities.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Homework-related

Main Points Raised

  • One participant outlines the equation e^z = 1 and expresses that they have reached a point of uncertainty after identifying that sin y = 0 leads to y = 2πK, where K is an integer.
  • Another participant suggests expressing the right-hand side of e^z = 1 + i in polar form to facilitate solving the equation.
  • A participant reiterates their earlier steps for e^z = 1 and questions the possible values for cos y after establishing that sin y = 0.
  • For the equation e^z = 1 + i, a participant notes that sin y = 1 leads to y = π/2 but challenges this conclusion by stating that the equation e^x sin y = 1 does not necessarily imply sin y = 1, suggesting an alternative approach by squaring and adding the equations to eliminate y.

Areas of Agreement / Disagreement

Participants express differing views on how to proceed with the solutions, particularly regarding the implications of the trigonometric identities and the use of polar forms. The discussion remains unresolved as participants explore various methods without reaching consensus.

Contextual Notes

Some assumptions regarding the values of x and y remain unaddressed, and there are unresolved mathematical steps in the proposed approaches. The dependence on definitions of trigonometric functions and polar coordinates is also noted.

racland
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Complex Analysis:
Find all solutions of:
(a) e^z = 1
(b) e^z = 1 + i
 
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Have you at least made attempts to solve them?
 
How fascinating!
We are all desirous to see what you have done so far! :smile:
 
So far I got:
e^z = 1
I know e^z = e^x (cos y + i Sin y)
Then,
e^x cos y = 1
e^x sin y = 0
I know that for sin y = 0, y = 2 pi * K, where k is an integer.
After this step I'm stuck!

The second problem: e^z = 1 + i
e^x cos y = 1
e^x sin y = 1
I order for sin y = 1, y = pi/2. Now what...
 
can you express the RHS in polar form?
 
racland said:
So far I got:
e^z = 1
I know e^z = e^x (cos y + i Sin y)
Then,
e^x cos y = 1
e^x sin y = 0
I know that for sin y = 0, y = 2 pi * K, where k is an integer.
After this step I'm stuck!
Actually y= [itex]\pi K[/itex], since [itex]sin(\pi)= 0[/itex] also. Now, what values can cos y have? And then what is ex?


The second problem: e^z = 1 + i
e^x cos y = 1
e^x sin y = 1
I order for sin y = 1, y = pi/2. Now what...
No, exsin y= 1 does NOT tell you that sin y= 1! You might try this: square each equation and add. That will get rid of y so you can find ex (you don't really need to find x itself).
 

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