Evaluate log base 3 of a/3

$\log_{3} (\frac{a}{3})$

Step 1

Rewrite $\frac{a}{3}$ as $a \cdot 3^{- 1}$ .

$\log_{3} (a \cdot 3^{- 1})$

Step 2

Rewrite $\log_{3} (a \cdot 3^{- 1})$ as $\log_{3} (a) + \log_{3} (3^{- 1})$ .

$\log_{3} (a) + \log_{3} (3^{- 1})$

Step 3

Use logarithm rules to move $- 1$ out of the exponent.

$\log_{3} (a) - \log_{3} (3)$

Step 4

Logarithm base $3$ of $3$ is $1$ .

$\log_{3} (a) - 1 \cdot 1$

Step 5

Multiply $- 1$ by $1$ .

$\log_{3} (a) - 1$

Step 6

Rewrite $\log_{3} (a)$ using the change of base formula.

The change of base rule can be used if $a$ and $b$ are greater than $0$ and not equal to $1$ , and $x$ is greater than $0$ .

$\log_{a} (x) = \frac{\log_{b} (x)}{\log_{b} (a)} - 1$

Substitute in values for the variables in the change of base formula, using $b = 10$ .

$\frac{\log (a)}{\log (3)} - 1$