Difference of Logarithms/Proof 2

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Theorem

$\log_b x - \log_b y = \map {\log_b} {\dfrac x y}$


Proof

\(\ds \log_b x - \log_b y\) \(=\) \(\ds \frac {\log_e x} {\log_e b} - \frac {\log_e y} {\log_e b}\) Change of Base of Logarithm
\(\ds \) \(=\) \(\ds \frac {\log_e x - \log_e y} {\log_e b}\)
\(\ds \) \(=\) \(\ds \frac {\log_e \left({\frac x y}\right)} {\log_e b}\) Difference of Logarithms: Proof for Natural Logarithm
\(\ds \) \(=\) \(\ds \log_b \left({\frac x y}\right)\) Change of Base of Logarithm

$\blacksquare$