1. The problem statement, all variables and given/known data y1(x,t) = 5.00sin(2.00x - 10.0t) y2(x,t) = 10.0cos(2.00x - 10.0t) a) Prove that the wave that is the result of the superposition is a function of sin. b) What's the phase angle and amplitude of said wave? 2. Relevant equations y = y1 + y2 3. The attempt at a solution Initially I figured I'd work y2 into a sin function like this: y2(x,t) = 10.0sin(2.00x - 10.0t + π/2). Then take the y = y1 + y2 formula: y = 5.00(sin(2.00x - 10.00t) + 2sin(2.00x - 10.0t + π/2)) Then I'd set 2.00x - 10.0t = a & π/2 = b, and rework the latter with: sin(a+b) = sin(a)*cos(b) + cos(a)*sin(b) But if I put that in the above equation, I just end up with y = 5.00sin(2.00x - 10.0t) + 10.0cos(2.00x - 10.0t) I checked around to find any formulas or theory about waves without the same amplitudes and whatnot, but my book has only the one case (same direction, same A, sin). Any help is appreciated!