Solving Modulus Equation: Find z=a+bi

  • Thread starter Thread starter BloodyFrozen
  • Start date Start date
  • Tags Tags
    Modulus
Click For Summary

Homework Help Overview

The problem involves finding all complex numbers of the form ##z=a+bi## such that the modulus of ##z## equals the modulus of ##z^{2}+1##. Participants are discussing the implications of this equation and the steps taken to manipulate it.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants have attempted to expand the components of the equation and equate the moduli. There is a focus on the correct expression for ##z^{2}## and the subsequent implications of the modulus equality.

Discussion Status

There is ongoing dialogue regarding the correct formulation of the equation, particularly the signs in the expression for ##z^{2}##. Some participants are correcting previous errors and ensuring consistency throughout their work.

Contextual Notes

Participants are addressing errors in their initial attempts, specifically regarding the signs in the expansion of ##z^{2}##. There is an emphasis on ensuring all parts of the equation are accurately represented following corrections.

BloodyFrozen
Messages
353
Reaction score
1

Homework Statement


Find all ##z=a+bi## such that:
[tex]|z|=|z^{2}+1|[/tex]


Homework Equations


The Attempt at a Solution


I expanded the components.
[tex]|z|=|z^{2}+1|[/tex]
[tex]z^{2}=a^2-b^2+2abi[/tex]
[tex]\sqrt{a^{2}+b^{2}}=\sqrt{(a^{2}-b^{2}+1)^{2}+(2ab)^{2}}[/tex]
[tex]a^2+b^2=(a^{2}-b^{2}+1)^{2}+(2ab)^{2}[/tex]
[tex]0=a^{4}+2a^{2}b^{2}+b^{4}+a^{2}-3b^{2}+1[/tex]

I don't see what to do now...
 
Last edited:
Physics news on Phys.org
BloodyFrozen said:

Homework Statement


Find all ##z=a+bi## such that:
[tex]|z|=|z^{2}+1|[/tex]


Homework Equations


The Attempt at a Solution


I expanded the components.
[tex]|z|=|z^{2}+1|[/tex]
[tex]z^{2}=a^2+b^2+2abi[/tex]
That should be [itex]-b^2[/itex], not [itex]+b^2[/itex].
 
jbunniii said:
That should be [itex]-b^2[/itex], not [itex]+b^2[/itex].

Right. Let me just go fix that.

Edit. Fixed
 
BloodyFrozen said:
Right. Let me just go fix that.

Edit. Fixed

Well, you fixed it in the first line where it appeared, but you still need to fix it everywhere else.
 
jbunniii said:
Well, you fixed it in the first line where it appeared, but you still need to fix it everywhere else.

I fixed then end before, I just forgot to change the middle parts.
 

Similar threads

  • · Replies 17 ·
Replies
17
Views
2K
Replies
20
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
2
Views
2K
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K