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Complex number question

  • Thread starter Ry122
  • Start date
565
2
Find z
Question:
z^3+i=0
My attempt:
z^3=-i
use z^n=|z|^(n) x e^((i)(n)(theta))
n = 3
|z|=1
theta = -pie/2
Is this correct?
 

Answers and Replies

1,395
0
if z=i

z^2=-1 z^3=-1*i >>-i
 
tiny-tim
Science Advisor
Homework Helper
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… one step at a time …

z^3+i=0
My attempt:
z^3=-i
use z^n=|z|^(n) x e^((i)(n)(theta))
Hi Ry122! :smile:

You must be much more logical, or you'll make mistakes. :frown:

Do it one step at a time.

You know z^3=-i.

So - first step - write -i in the form r.e^(i theta).

What is it?

Then divide theta by 3. :smile:

Oh … and how many different solutions are there? :rolleyes:
 

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