Logarithm with Different Base: Solving for x/y

In summary, the problem given is to find the value of x/y when the equation 2*\log_2 (x-2y)=\log_3 (xy) is given. The attempt at a solution involved using the logarithm property \log_bx = \frac{\log_ax}{\log_ab} to simplify the equation, but it was discovered that \log_2 3 is not an integer, making it impossible to solve the equation.
  • #1
songoku
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Homework Statement


Hi everyone

I need help for this problem :

If [tex]2*\log_2 (x-2y)=\log_3 (xy)[/tex] , find [tex]\frac{x}{y}[/tex]


Homework Equations


[tex]\log_bx = \frac{\log_ax}{\log_ab}[/tex]


The Attempt at a Solution


[tex]2*\log_2 (x-2y)=\log_3 (xy)[/tex]

[tex]\log_2 (x-2y)^2=\log_3 (xy)[/tex]

[tex]\frac{\log_2 (x-2y)^2}{\log_2 2}=\frac{\log_2 (xy)}{\log_2 3}[/tex]

[tex]\log_2 (x-2y)^2 * \log_2 3 = \log_2 (xy)[/tex]

Then, I stuck ...

Thx :)
 
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  • #2
Are you sure you wrote the question down correctly? I ask because log23 is not an integer and you be basically computing (x-2y)k=xy where k is not an integer (so you'd not be able to find x/y)
 
  • #3
Hi rock.freak667

At least that's the whole question that was given to me by my friend. Your post assure me that this question can't be solved.

Thx a lot for pointing out that [tex]\log_2 3[/tex] is not an integer :smile:
 

FAQ: Logarithm with Different Base: Solving for x/y

What is a logarithm with different base?

A logarithm is a mathematical function that represents the relationship between a number and its exponent. A logarithm with a different base simply means that the number and exponent are being compared using a different number as the base.

How do you calculate a logarithm with different base?

The formula for calculating a logarithm with a different base is logb(x) = log(x) / log(b), where x is the number and b is the base. This can also be written as logb(x) = ln(x) / ln(b), where ln is the natural logarithm function.

What is the significance of using a different base in logarithms?

Using a different base in logarithms can provide a different perspective on the relationship between a number and its exponent. It can also be useful in solving equations or simplifying calculations.

Can a logarithm with different base be negative?

Yes, a logarithm with different base can be negative. This can occur when the number being compared is less than the base, resulting in a negative exponent.

How is a logarithm with different base related to exponential functions?

A logarithm with different base is essentially the inverse of an exponential function. In other words, it represents the exponent that a number would need to be raised to in order to get the given value. For example, log2(8) = 3 can also be written as 23 = 8.

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