Question

Помогите решить
1+tg^2 2y
1+ctg^2 3x
sin(x+3y)
cos(3x+y)

Answer 1

1+tg^2 2y=1/cos²2y
1+ctg^2 3x=1/sin²3x
sin(x+3y)=sinxcos3y+cosxsin3y
cos(3x+y) =cos3xcosy-sin3xsiny