we can find Equation (5) by dividing po by n0, and write an equation with respect to Ei.
However since equation (3) is a special form of (1) and (2), [when Ef=Ei] we can obtain equation (5) from
any arbitrary Ef.
However, since eq (5) consists of constants only, it will give a result Ef=Ei which contradicts to eq(4).
I know I am wrong, but from which step did I get this wrong?