Question

Знайти похідну
ctg x/4 + 3cos4x

Answer 1

$(ctg frac{x}{4}+3cos4x)' =(ctg frac{x}{4})'+(3cos4x)'=(frac{x}{4})'* frac{-1}{sin^2(frac{x}{4})} +3(cos4x)'= \ =frac{1}{4}* frac{-1}{sin^2(frac{x}{4})} +3*4(-sin4x)= - frac{1}{4sin^2( frac{x}{4} )} -12sin4x$