1. The problem statement, all variables and given/known data What is the equation for the superposition of 2 waves? 2. Relevant equations 3. The attempt at a solution Displacement of the first wave is D1 = Asin(k1x - ω1t) Displacement of second wave is D2= Asin(k2x - ω2t) Add together: D1 + D2 = 2Acos[(k1-k2)x/2 - (ω1 - ω2)t/2]*sin[(k1 + k2)x/2 - (ω1 + ω2)t/2] But this isn't in terms of what the problem is asking! Help, can the form be changed somehow? Is there a way to reduce the k1 and k2 so that it is in that form?