Дано F(x)=4sin52x надо найти F’(π\8)

Question

Дано F(x)=4sin52x надо найти F’(π\8)

Answer 1

 F(x)=4sin52x

F'(x) = 4cos(52x)*52 = 208cos(52x)

F'(π/8) =  208cos(52*π/8) = 208cos(6,5π) = 208cos(π/2) = 208*0 = 0