I am required to show that (i)in the upper limit of very high energies, the Born and eikonal identities are identical. (ii)that the eikonal amplitude satisfies the optical theorem. Regarding (i) I think it will involve changing from an exponential to a trig(Euler's theorem) but I could be wrong. The textbook says that sinχ=χ (I think that χ is the profile function). Regarding (ii) I am clueless. I am trying to do postgrad physics after a period of 6 years since undergrad!! Please help!