Question

ПОМОГИТЕ С ПРОИЗВОДНОЙ

Answer 1

$y`=(-\frac{1}{cos2x}+cos\frac{\pi}{3})`=(-(cos2x)^{-1})`+(cos\frac{\pi}{3})`=-2sin2xcos2x^{-2}=\\=-\frac{2sin2x}{cos^22x}=-2\frac{tg2x}{cos2x}=-2\frac{tg\frac{\pi}{4}}{cos\frac{\pi}{4}}=-2\frac{2}{\sqrt2}=-2\sqrt2$