1-9 Interference of waves



The resultant wave has the same wavelength and frequency as that of wave 1 and wave 2.

 Using the following trigonometric identity


we may write yres(x,t) as

Two waves y1(x,t) and y2(x,t) of the same amplitude and frequency, moving in the same direction on the same string, interfere to produce the resultant wave yres(x,t)