 The mathematical representation of a radial wave is given by

where formula_13, formula_14 is the wavelength, formula_15 is frequency of the wave and formula_16 is the phase of the wave at the slits at time t=0.The wave at a screen some distance away from the plane of the slits is given by the sum of the waves emanating from each of the slits.To make this problem a little easier, we introduce the complex wave formula_17, the real part of which is equal to formula_18
The absolute value of this function gives the wave amplitude, and the complex phase of the function corresponds to the phase of the wave.