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
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