1. The problem statement, all variables and given/known data The length of the photon waves which are under Compton scattering ( compton scattering is applied on them) is measured in the angle =90 degree.If ΔΛ/Λ is 1.5 %,what is the length of the waves of the falling photons? 2. Relevant equations 3. The attempt at a solution The only problem here is ΔΛ/Λ = 1.5 %, I dont know how to relate that to the above formula..