Finding a Conformal Function for Mapping D1 onto the Unit Disc D2

In summary, the problem is to find a conformal function that maps the region D_1, which is defined by Re(z)<0 and 0<Im(z)<2π, onto the unit disc D_2. The attempt at a solution involves using a series of conformal mappings to gradually transform D_1 into D_2, including the functions e^z, √z, (z+1)/(1-z), z^2, ze^(-iπ/2), and (i-z)/(z+i). However, there is a typo in the original post, as D_1 should be defined by Re(z)<0 instead of Re(z)>0.
  • #1
skrat
748
8

Homework Statement


Find conformal function that maps ##D_1=\left \{ z;Re(z)>0,0<Im(z)<2\pi \right \}## on to ##D_2## where ##D_2## is unit disc.

Homework Equations


The Attempt at a Solution



Ok, I haven't got any problems with conformal mapping but I have huge problems with function composition and I would need some help here...

Firstly, ##f_1=e^z## maps from ##D_1## into unit disc without ##Re(z)>0## axis, so to this object I now apply ##f_2=\sqrt{z} ## which gives me upper half of unit disc (real exis not included!).

Now ##f_3=\frac{z+1}{1-z}## maps the upper unit disk into first quadrant. Applying ##f_4=z^2## extends my area on to upper half plane. Rotating it with ##f_5=ze^{-i\pi /2}## and again using Mobius transformation ##f_6=\frac{i-z}{z+i}## gives me that unit disk.

Now the question is of course what ##f=f_6\circ f_5\circ f_4\circ f_3\circ f_2\circ f_1##?

Does it even make any sense to do that?
 
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  • #2
skrat said:

Homework Statement


Find conformal function that maps ##D_1=\left \{ z;Re(z)>0,0<Im(z)<2\pi \right \}## on to ##D_2## where ##D_2## is unit disc.


Homework Equations





The Attempt at a Solution



Ok, I haven't got any problems with conformal mapping but I have huge problems with function composition and I would need some help here...

Firstly, ##f_1=e^z## maps from ##D_1## into unit disc without ##Re(z)>0## axis,
##f_1(1+i\pi)=e^{1+i\pi}=e^1 e^{i\pi}= -e## is not in the unit disc.
 
  • #3
Of course not. It even doesn't have to be.

There is a typo in my original post. Instead of ##D_1=\left \{ z;Re(z)>0,0<Im(z)<2\pi \right \}## it is ##D_1=\left \{ z;Re(z)<0,0<Im(z)<2\pi \right \}##
 

Related to Finding a Conformal Function for Mapping D1 onto the Unit Disc D2

1. What is function composition?

Function composition is the process of combining two or more functions together to create a new function. The output of one function becomes the input of another, creating a chain of operations.

2. What is the purpose of function composition?

The purpose of function composition is to break down complex problems into smaller, more manageable parts. It allows for reusability and modularity in code, making it easier to maintain and debug.

3. How is function composition different from function chaining?

Function composition involves creating a new function by combining two or more existing functions, while function chaining involves calling multiple functions in a sequence, with the output of one function being the input of the next.

4. What are the benefits of function composition?

Function composition allows for code reuse, modularity, and easier maintenance. It also promotes a more functional programming style, making code more declarative and easier to reason about.

5. Are there any limitations to function composition?

Function composition can become complex and difficult to read if there are too many functions involved. It also may not be suitable for all types of problems, as some may be better solved using other techniques such as loops or recursion.

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