Find f '(x) and f "(x) if : f(x) = x

x

Not sure how to do this any help would be appreciated.

2. Originally Posted by The Math Man
Find f '(x) and f "(x) if : f(x) = x

x

Not sure how to do this any help would be appreciated.
$f(x) = \frac{\ln{x}}{x}$

quotient rule ...

$f'(x) = \frac{x \cdot \frac{1}{x} - \ln{x} \cdot 1}{x^2}$

clean it up, and use the quotient rule again to find $f''(x)$