How to Solve Complex Logarithmic Equations

In summary, the problem is to solve a logarithmic equation and apply basic log rules and properties, such as the change of base formula, to find the solution.
  • #1
zaddyzad
149
0

Homework Statement



A) Solve LogX^(LogX) = 4
B) Log3 X - Log27 X = 4/3

Homework Equations



Basic 3 log rules: 1. Logc(MN) = LogcM + logcN 2. Logc(M/N) = LogcM - LogcN 3. LogcM^p = pLogcM

The Attempt at a Solution


I have no idea how to start either.
 
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  • #2
Find the "Relevant equations" for part 2 of the format.

What is or are the bases for question #B ? Also, what is or are the bases for #A?

Take care of those, and helping you will be easier; otherwise your problem description and question are not understandable.

zaddyzad said:

Homework Statement



A) Solve LogX^(LogX) = 4
B) Log3 X - Log27 X = 4/3


Homework Equations





The Attempt at a Solution


I have no idea how to start either.
 
  • #3
symbolipoint said:
Find the "Relevant equations" for part 2 of the format.

What is or are the bases for question #B ? Also, what is or are the bases for #A?

Take care of those, and helping you will be easier; otherwise your problem description and question are not understandable.

For part A) the base is 10, therefor that's why it isn't written, and for B it's the 3 and 27.
 
  • #4
You still need to decide which relevant equations or properties you need for part 2 of the format template. One of them should be the change of base formula for question #B.
 
  • #5
Those are the only log formulas I know and have learned. This is an extend question.
 
  • #6
If you have a log(x)^(anything) what do you get?
 
  • #7
You know the relation following from definition of logarithm:
[tex]a ^{log_a(x)}=x[/tex]

Apply to the base 27 logarithm:

[tex]27 ^{log_{27}(x)}=x[/tex]Take the base 3 logarithm of both sides: you find how log27(x) is related to log3(x).

ehild
 
  • #8
zaddyzad said:

Homework Statement



A) Solve LogX^(LogX) = 4
B) Log3 X - Log27 X = 4/3

Homework Equations



Basic 3 log rules: 1. Logc(MN) = LogcM + logcN 2. Logc(M/N) = LogcM - LogcN 3. LogcM^p = pLogcM

The Attempt at a Solution


I have no idea how to start either.
I assume that A) is:
Solve [itex]\displaystyle \log\left(x^{\log(x)}\right)=4\ ,\ \ [/itex] of course that is a base 10 logarithm, as you noted elsewhere.​
Use the [itex]\displaystyle \log_{\,c}\left(x^{p}\right)=p\,\log_{\,c}(x)\ \ [/itex] property on A).

Have you learned the change of base formula? Use it for B).
 
  • #9
There is one more property that you can make use of here,
[tex]log_{a^c} b=\frac{log_a b}{c}[/tex]
 

1. What is a complex logarithm?

A complex logarithm is a type of mathematical function that deals with complex numbers, which have both a real and imaginary component. It is defined as the inverse of the exponential function, and is denoted as logb(z), where b is the base and z is the complex number.

2. How do you solve complex logarithmic equations?

To solve a complex logarithmic equation, you can use the properties of logarithms, such as the power rule and product rule, along with algebraic manipulation, to simplify the equation. Then, you can use the definition of a complex logarithm to convert it into an exponential form, which can be solved using basic algebra.

3. What is the principal value of a complex logarithm?

The principal value of a complex logarithm is the value that satisfies the definition of a complex logarithm, where the imaginary part of the logarithm is between -π and π. This value is also known as the principal branch of the complex logarithm.

4. Can complex logarithms have multiple solutions?

Yes, complex logarithms can have multiple solutions, also known as branches. This is because the exponential function is periodic, so there are multiple values of z that can satisfy the equation logb(z) = w, where w is a complex number.

5. What are some real-world applications of complex logarithms?

Complex logarithms have various applications in fields such as physics, engineering, and economics. They are used to model exponential growth and decay, as well as in circuit analysis and signal processing. They are also used in complex analysis, which has applications in fluid dynamics, electromagnetism, and quantum mechanics.

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