Which of the following is equivalent to [tex]\frac{\log _9(m)}{\log (m)}[/tex]?

Choose 1 answer:
A. [tex]\log (9)[/tex]
B. [tex]\log _9(1)[/tex]
C. [tex]\frac{1}{\log (m)}[/tex]
D. [tex]\frac{1}{\log (9)}[/tex]



Answer :

To solve the expression [tex]\(\frac{\log_9(m)}{\log(m)}\)[/tex], we can use the properties of logarithms. Let's go through the steps carefully.

1. Understanding the Change of Base Formula:
The change of base formula for logarithms states that:
[tex]\[ \log_b(a) = \frac{\log_k(a)}{\log_k(b)} \][/tex]
where [tex]\(b\)[/tex] and [tex]\(a\)[/tex] are positive real numbers and [tex]\(k\)[/tex] is any positive real number different from 1.

2. Applying the Change of Base Formula:
We can rewrite [tex]\(\log_9(m)\)[/tex] using the change of base formula. Let’s choose the common logarithm (base 10) for simplicity:
[tex]\[ \log_9(m) = \frac{\log(m)}{\log(9)} \][/tex]

3. Substitute [tex]\(\log_9(m)\)[/tex] into the Original Expression:
Now, substitute [tex]\(\log_9(m)\)[/tex] into the original expression [tex]\(\frac{\log_9(m)}{\log(m)}\)[/tex]:
[tex]\[ \frac{\log_9(m)}{\log(m)} = \frac{\frac{\log(m)}{\log(9)}}{\log(m)} \][/tex]

4. Simplify the Expression:
Simplify the fraction:
[tex]\[ \frac{\frac{\log(m)}{\log(9)}}{\log(m)} = \frac{\log(m)}{\log(9) \cdot \log(m)} \][/tex]
Since [tex]\(\log(m)\)[/tex] is in both the numerator and the denominator (given that [tex]\(\log(m) \neq 0\)[/tex]), we can cancel [tex]\(\log(m)\)[/tex]:
[tex]\[ \frac{1}{\log(9)} \][/tex]

Therefore, the expression [tex]\(\frac{\log_9(m)}{\log(m)}\)[/tex] simplifies to [tex]\(\frac{1}{\log(9)}\)[/tex].

So, the correct choice is:
[tex]\[ \boxed{D \: \frac{1}{\log(9)}} \][/tex]