Q. If $f^{'}(x) = sin(\log{x)\ and\ y = f}\left( \frac{2x + 3}{3 - 2x} \right)$, then $\frac{dy}{dx}\$at $x = 1$ is equal to

A) 6 sin log (5)
B) 5 sin log (6)
C) 12 sin log (5)
D) 5 sin log (12)
Explanation

(c)
$\frac{dy}{dx} = f^{'}\left( \frac{2x + 3}{3 - 2x} \right)\frac{d}{dx}\ \left( \frac{2x + 3}{3 - 2x} \right)$
$= {\ sin}{\log\left( \frac{2x + 3}{3 - 2x} \right)\left( \frac{(3 - 2x)(2) - (2x + 3)( - 2)}{(3 - 2x)^{2}} \right)}$
$= \frac{12}{(3 - 2x)^{2}}\sin\left\{ \log\left( \frac{2x + 3}{3 - 2x} \right) \right\}$
$\ \therefore\ \ \left( \frac{dy}{dx} \right)_{x = 1} = \frac{12}{(3 - 2)^{2}}.\sin{\log{5 = 12\sin{\log{5\ }}}}$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.