complex numbers

[shiva kumar]

complex numbers have a wide variety of applications in communications but why are we considering imaginary numbers if they are not existing?
i mean according to fourier analysis any wave can be expressed as sum of exponential functions
and e^ix=cosx+isinx but how are we expressing a wave that is physically existing in terms of complex quantities which contains imaginary quantities which doesnt have any physical existance?

[niraj.kumar]

shiva complex number is not all imaginery it solve lots of pratical problem in aviation