The differential equation, corresponding to sinusoidal waves, represented by
y = a sin(ωt – kx)
has the form \(\frac{\partial ^2y}{\partial x^2}=\frac{1}{v^2}\frac{\partial ^2 y}{\partial t^2}(v=\frac{ω}{k})\)
The general functional equation, for a periodic wave
y = af (ωt - kx)
(1) can represent a sinusoidal wave but its differential equation form would be different from above
(2) cannot represent a sinusoidal wave but its differential equation form would be same as above
(3) cannot represent a sinusoidal wave; its differential equation form would also be different from above
(4) can represent a sinusoidal wave; its differential equation form would also be the same as above