Question

y=cos4x-x/2
Найти: y`(п/4)

Answer 1

$y'(x) = (cos(x) - frac{x}{2})' = -4sin(4x) - frac{1}{2};\ y'(frac{pi}{4}) =-4sin(pi) - frac{1}{2} = -frac{1}{2};$