do not copy from chegg, it seems not right. thank you

3. Derive an expression for the polydisper- sity found in a linear polycondensation of equimolar amounts of A-A- and B-B-type monomers. What is the limiting value? How does this limiting compare to that calculated for a free radical polymerization? Explain why the polydispersity of a sample of (say) polystyrene polymerized to a high degree of conversion differs from this