Find the Intervals Where $f ( x ) = \frac { \log 9 x } { x }$

question 27

Multiple Choice

Find the intervals where $f ( x ) = \frac { \log 9 x } { x }$ is increasing and where it is decreasing.

• A) increasing: \(( 9 e , \infty )\), decreasing: \(( 0,9 e )\)
• B) increasing: \(\left( 0 , \frac { e } { 9 } \right)\), decreasing: \(\left( \frac { e } { 9 } , \infty \right)\)
• C) increasing: \(( 90 , \infty )\), decreasing: \(( 0,90 )\)
• D) increasing: \(\left( 0 , \frac { 9 } { 10 } \right)\), decreasing: \(\left( \frac { 9 } { 10 } , \infty \right)\)