1-9 Interference of waves

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

Amplitude

 Using the following trigonometric identity

 

we may write y_res(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 y_res(x,t)