Complex Functions Homework: Find Limit

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Homework Help Overview

The discussion revolves around finding the limit of a complex function, with participants sharing various attempts and interpretations of the problem. The context includes references to complex analysis concepts such as limits, series expansions, and analyticity.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants explore different approaches to finding the limit, including using series expansions and questioning the analyticity of certain functions. Some express confusion over specific substitutions and the implications of using complex conjugates.

Discussion Status

The discussion is active, with multiple interpretations being explored. Some participants provide guidance on the use of series and limits, while others express uncertainty about specific steps and concepts. There is no explicit consensus on the limit itself.

Contextual Notes

Some participants question the assumptions regarding analyticity and the behavior of functions as they approach limits. There are references to homework constraints and the need for clarity in the problem setup.

m_s_a
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Homework Statement


Find the limit :

http://www.a7bk-a-up.com/pic/uDs93333.bmp
http://www.a7bk-a-up.com/pic/zAP94166.bmp


The Attempt at a Solution


http://www.a7bk-a-up.com/pic/g0Q93947.bmp

Homework Statement








result


The Attempt at a Solution

 
Physics news on Phys.org
Last Qiustion::biggrin:
http://www.a7bk-a-up.com/pic/Nww95795.bmp
 
please wait:zzz:
 
m_s_a said:

Homework Statement


Find the limit :

http://www.a7bk-a-up.com/pic/uDs93333.bmp
http://www.a7bk-a-up.com/pic/zAP94166.bmp


The Attempt at a Solution


http://www.a7bk-a-up.com/pic/g0Q93947.bmp

Homework Statement








result


The Attempt at a Solution


cos(pi/2)+i*sin(pi/2)=i, not i^(1/2). ?
 
m_s_a said:
Last Qiustion::biggrin:
http://www.a7bk-a-up.com/pic/Nww95795.bmp

But what? Isn't the limit still 1?
 
Dick said:
cos(pi/2)+i*sin(pi/2)=i, not i^(1/2). ?

By imposing
I said let w=i===>w^2=-1
 
Dick said:
But what? Isn't the limit still 1?

Yes,
Find this limit
 
m_s_a said:
By imposing
I said let w=i===>w^2=-1

I don't understand that at all.
 
m_s_a said:
Yes,
Find this limit

Substitute zbar for z in the power series. What's wrong with that?
 
  • #10
  • #11
It doesn't have to be analytical. You've shown using the series (or l'Hopital) that if z_n is a series of complex numbers approaching 0, then sin(z_n)/z_n->1. z_n* is also a series of complex numbers approaching 0. The series expansion holds for ANY z.
 
  • #12
Like this
http://www.a7bk-a-up.com/pic/ydi48834.bmp
 
  • #13
Infact:
http://www.a7bk-a-up.com/pic/LpB47687.jpg
delta=?
 
  • #14
Sure. |(sin(z*)/z*|=|sin(z)/z|. Because (sin(z)/z)*=(sin(z*)/z*) and |z|=|z*|. So you don't need analyticity, correct?
 
  • #15
Dick said:
Sure. |(sin(z*)/z*|=|sin(z)/z|. Because (sin(z)/z)*=(sin(z*)/z*) and |z|=|z*|. So you don't need analyticity, correct?

Dear: Dick
correct 100%.


Thank you for answering me
Thank you very much:blushing:
In Arabic:
:biggrin:شكرًا جزيلاً
 
  • #16
Sure. Sorry, I'm not good at the script. afwan.
 
  • #17
Dick said:
Sure. Sorry, I'm not good at the script. afwan.

O. My Dod
afwan
very very Excellent
Rather than to learn English
You have learned Arabic
 
  • #18
shukran, afwan, is about as far as I go. Oh, and salam alekum. That's it. I don't even remember how to count, even though this is a math site. So you might want to keep learning english. :)
 
Last edited:
  • #19
show that :
 

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