Sketch one cycle of the sine curve. y = -3 sin 4theta

How do i do this activity, is appreciated

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Aconstruction worker has rope 9 m long he needs to cut it in pieces that are each 3 /5 m long how many such pieces can he cut without having any rope leftover?