ВЫЧИСЛИТЕ ИНТЕГРАЛ COS 3x!!!
∫cos(3x)dx=sin(3x)/3 π/₄|π/³=(1/3)*(sin(3*(π/3))-sin(3*(π/4))=
=(1/3)*(sin(π)-sin(3π/4))=(1/3)*(0-√2/2)=(1/3)*(-√2/2)=-√2/6.