Understanding Logarithmic Properties: Explained with Examples

AI Thread Summary
The discussion clarifies the logarithmic property that states log base c of a raised to b equals b times log base c of a. The initial confusion arose from misapplying the formula, leading to incorrect calculations. The correct expression is log_c(a^b) = b * log_c(a), which can be proven using exponential properties. Participants emphasize the importance of understanding the relationship between logarithms and exponents. This clarification helps resolve discrepancies in calculations involving logarithmic expressions.
Rafe
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Okay i did a search for logarithmic properties and logarithms and couldn't seem to find an explanation for how this particular property works.
(log base c of a ) ^ b = b (log base c of a)
when i input simple numbers like :
PHP:
a=4
b=3
c=2
Log base 2 of 4 obvioussly the answer is 2, but
2^3 /= (does not equel) 3 x 2.
i dont' know how to make sense of this discrepency. i imagine I'm just reading it wrong.
 
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hmmm the right formula is log_c(a)^b=blog_c(a)

edit: heh, I am tired =P
 
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because (c^a)^b=c^{a*b}.
 
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Actually the correct formula is:

\log_c(a^b) = b\log_c (a)

This can be proven by taking the base c exponential of each side:

c^{\log_c(a^b)} = a^b

c^{b\log_c (a)} = (c^{\log_c (a)})^b= (a)^b
 
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