# Logarithm Question

• Jun 7th 2008, 10:46 AM
SolidSnakeXC
Logarithm Question
Hi,

I have a question regarding logarithms. The question that I have is this:

I need to combine the bases of two different logs: LogaX=C and LogbX=C so how do I turn that into LogabX?

• Jun 7th 2008, 10:57 AM
Moo
Hi,

Quote:

Originally Posted by SolidSnakeXC
Hi,

I have a question regarding logarithms. The question that I have is this:

I need to combine the bases of two different logs: LogaX=C and LogbX=C so how do I turn that into LogabX?

Here is how I do :

the general formula states :

$\log_a X=\frac{\ln X}{\ln a}$

where $\ln$ is the neperian logarithm ( $\ln=\log_e$)

$\log_b X=\frac{\ln X}{\ln b}$

$\ln_{ab} X=\frac{\ln X}{\ln ab}=\frac{\ln X}{\ln a+\ln b}$

Try to find what you want by taking the inverse :)
• Jun 7th 2008, 10:59 AM
SolidSnakeXC
Thank you!