(b) $10^{- x\tan x}\frac{d}{dx}(10^{x\tan x})$ $= 10^{- x\tan\ x}10^{x\tan\ x}\log{10(\tan{x + x\sec^{2}{x)}}}$ $= \log{10(\tan{x + x\sec^{2}{x)}}}$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.