Hi everyone,I've joined this forum specially to get help for Compton effect derivation. I'm trying and trying but can't solve it. please anyone help, explain it in a really easy way.here's the derivation from a site:Consider a photon of frequency u1 and wavelength l1 strikes a stationary electron of rest mass mo. After collision the photon is scattered at an angle of q with its original line of action. While electron moves forward at an angle of f with its original direction. Energy of photon before collision = E1= hu1Energy of electron before collision = E2= moc2Energy of photon after collision = E1`= hu2Energy of electron after collision = E2` = mc2Since the collision between photon and electron is elastic. Therefore energy and momentum will be conserved.Total energy before collision = Total energy after collisionE1 E2= E1` E2`hu1 moc2= hu2 mc2hu1- hu2= mc2– moc2h(u1-u2) = c2(m – mo)……………….(1)momentum of photon before collision = h /l1Momentum of electron before collision = 0Momentum of photon after collision = h /l2Momentum of electron after collision = mvMOMENTUM EQUATION ALONG X-AXISh/l1 0 = h/l2Cosq mvCosfh/l1= h/l2Cosq mvCosf………….(2)MOMENTUM EQUATION ALONG Y-AXIs0 0 = h/l2Sinq (-mvSinf)h/l2Sinq-mvSinf= 0……………….(3)Solving (1) , (2) and (3), we get the following result:1/u2– 1/u1= h/moc2(1- Cosq) ………….(4)c(1/u2– 1/u1) = hc/moc2(1- Cosq)c/u2– c/u1= h/moc (1- Cosq)Butc/u=l,therefore,l2-l1= h/moc (1- Cosq)wherel2-l1= Compton’s shift in wavelengthh/moc is called Compton’s wavelength and its value is 2.426X10-12 m.CONCLUSIONThus the frequencyu2of scattered photon after the collision will be less than the original frequencyu1.------------------------so everything is clear but just from the step of solving eq 1,2, 3 .can anyone explain the missing steps? please help.