I have a problem solving a very simple logarithm problem.

$\displaystyle \log_8 128 = ?$

I know that the answer is 7/3 but i don't know how the answer is derived. Can someone explain all the step .

Thanks.

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- Jan 25th 2011, 02:04 AMvivek_master146Simple Logarithm
I have a problem solving a very simple logarithm problem.

$\displaystyle \log_8 128 = ?$

I know that the answer is 7/3 but i don't know how the answer is derived. Can someone explain all the step .

Thanks. - Jan 25th 2011, 02:16 AMCaptainBlack
- Jan 25th 2011, 02:46 AMProve It
- Jan 25th 2011, 02:49 AMDrSteve
You can also change to exponential form first and get a common base:

$\displaystyle \log_8 128 = x$

$\displaystyle 8^x=128$

$\displaystyle (2^3)^x=2^7$

$\displaystyle 2^{3x}=2^7$

$\displaystyle 3x=7$

$\displaystyle x=\frac{7}{3}$