Double slit interference

Phet - Two slit interference 

Hyperbolas

Different formulae for two sources interference 

Monochromatic wave    Slit separation       Interference pattern on the screen

Maxima order     Number of  maxima

Formula  for angular distribution of  maxima  and minima

Distance to the screen and  fringes separation

How Young made coherent wave

Deivation of equation for locations of Maxima and Minima using path difference and hyperbola formula.

First approximation if screen is far away - assympthotes of hypebola.

Second approximation if wavelength is small compare with distance between slits.

Derivation of position dependent intensity formula on the screen.