I have seen that the schrodinger wave equation is derived from the assumption that every wavefunction is of the form ψ(x,t)=A(cos(2πx/λ-2πηt)+isin(2πx/λ-2πηt)) where η is the frequency I can understand the real part of the equation. However, I am not able to understand the complex part of the equation. Why should every wavefunction have a complex part??? And why should that be isin( ) and not some other function? Does anybody have proof of this interpretation of the wavefunction?