What Are the Possible Values of 2^(-i)?

  • Context: MHB 
  • Thread starter Thread starter shen07
  • Start date Start date
  • Tags Tags
    Expression Imaginary
Click For Summary
SUMMARY

The discussion focuses on determining the possible values of the expression 2-i. Participants confirm that the logarithm is a multivalued function, leading to the conclusion that 2-i can be expressed as e-i(ln(2) + 2kπi), resulting in infinite solutions due to the arbitrary integer k. The function f(z) = 2z is also analyzed, revealing that if z is an integer, there is one solution; if z is rational, there are finite solutions; and for other complex numbers, there are finitely many solutions.

PREREQUISITES
  • Understanding of complex numbers and their properties
  • Familiarity with logarithmic functions, specifically complex logarithms
  • Knowledge of Euler's formula and its applications
  • Basic principles of multivalued functions in complex analysis
NEXT STEPS
  • Study the properties of complex logarithms and their applications
  • Explore Euler's formula in depth, particularly in relation to complex exponentiation
  • Investigate the implications of multivalued functions in complex analysis
  • Learn about the function f(z) = 2z and its behavior across different types of numbers
USEFUL FOR

Mathematicians, students of complex analysis, and anyone interested in the properties of complex exponentiation and logarithms.

shen07
Messages
54
Reaction score
0
Find all possible Values of:

2(-i)
 
Physics news on Phys.org
Re: Exercise

shen07 said:
Find all possible Values of:

2(-i)
What have you tried so far?

-Dan
 
Re: Exercise

well i have tried using

uv=evln(u)

and get cos(ln(2))-isin(ln(2))

but is it the solution because i am asked to find all the possible values
 
Re: Exercise

shen07 said:
well i have tried using

uv=evln(u)

and get cos(ln(2))-isin(ln(2))

but is it the solution because i am asked to find all the possible values

The logarithm is a multivalued function so

$$\log(a) = \ln|a|+iarg(a) $$
 
Re: Exercise

Yes i know that but here we have ln(2) and we can't write this in the above form.
 
Re: Exercise

shen07 said:
Yes i know that but here we have ln(2) and we can't write this in the above form.

$$2^{-i}=e^{-i\log(2)}=e^{-i(\ln|2|+2k\pi i)}$$
 
Re: Exercise

ZaidAlyafey said:
$$2^{-i}=e^{-i\log(2)}=e^{-i(\ln|2|+2k\pi i)}$$

but should we not apply complex logarithm ,i.e LOG to complex numbers only, here we should have use LN as far as i have understand. Correct me if i am wrong
 
Re: Exercise

shen07 said:
but should we not apply complex logarithm ,i.e LOG to complex numbers only, here we should have use LN as far as i have understand. Correct me if i am wrong

But 2 is still a complex number .

The function

$$e^{\log(2^{-i})}$$

is a multivalued function so it has infinite solutions .
 
Re: Exercise

ZaidAlyafey said:
But 2 is still a complex number .

The function

$$e^{\log(2^{-i})}$$

is a multivalued function so it has infinite solutions .

ok i understand what you are trying to say. 2 is also found in the complex plane, so we can apply this rule to it, hence obtaining several values with this arbitrary k.

Thanks
 
  • #10
Re: Exercise

For more information consider the following

$$f(z)=2^{z}$$ where $z$ is any complex number .

  1. if $z$ is an integer then the function has only one solution
  2. if $z$ is a rational number then it has finite number of solutions .
  3. If $z$ is any other complex number then it has finitely many solutions .
 
  • #11
Re: Exercise

ZaidAlyafey said:
For more information consider the following

$$f(z)=2^{z}$$ where $z$ is any complex number .

  1. if $z$ is an integer then the function has only one solution
  2. if $z$ is a rational number then it has finite number of solutions .
  3. If $z$ is any other complex number then it has finitely many solutions .
Thanks a Lot for this Idea..Will remember it..:D
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 36 ·
2
Replies
36
Views
6K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K