How do i combine two harmonic waves
y1=Asin(3x-5t)
y2=Asin(3x-5t-4)?
I know its y1+y2=the two combined. and you combine it through trig identity, but i am not very good with trig. can someone help me out? Much appreciated! (:

y1+y2= A ( sin(3x-5t) + sin (3x-5t+4) )

You have some trigonometric identity for sin(A+B). Change sin(3x-5t+4) with it, where A=3x-5t and B=4. You can then factor sin(3x-5t).