1. The problem statement, all variables and given/known data Determine the amplitude of the resultant wave when two sinusoidal waves having the same frequency and traveling in the same direction are combined, if their amplitudes are 3.0 cm and 4.0 cm and they differ in phase by [tex]\pi/2[/tex] rad 2. Relevant equations y(x,t)=a*sin(kx-wt) y(x,t)=b*sin(kx-wt+[tex]\phi[/tex]) [tex]\phi[/tex] phase difference sin a + sin b = 2sin 1/2(a+b) . cos 1/2(a-b) 3. The attempt at a solution Because the amplitudes are not the same couldn't solve it using the sum of sin.