graph the function: y = 4 sin 2 theta
in your notes or text you should have a summary of what
y = a sin kx looks like
a is the amplitude, and there are k complete sine curves from 0 to 2pi (360º).
so the amplitude is 4, there are 2 complete sine curves in the domain from 0 to 360, or the period of each sinewave is 360/2 or 180º