MCQ
જો $f(x) = {\log _x}(\log x),$ તો $f'(x)$ એ $x = e$ આગળ મેળવો.
  • A
    $e$
  • ${1 \over e}$
  • C
    $1$
  • D
    એક પણ નહીં

Answer

Correct option: B.
${1 \over e}$
(b) $f(x) = {\log _x}(\log x) = \frac{{\log (\log x)}}{{\log x}}$

==> $f'(x) = \frac{{\frac{1}{x} - \frac{1}{x}\log (\log x)}}{{{{(\log x)}^2}}} \Rightarrow f'(e) = \frac{{\frac{1}{e} - 0}}{1} = \frac{1}{e}$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free