Question

Minimize the following expression in (a) Sum of Products and (b) Product of Sums forms:

(A’ + B’ + D)(A’ + D’)(A + B + D’)(A + B’ + C + D)

Answer 1

It is already in the POS form.

(A’ + B’ + D)(A’ + D’) (A + B + D’)(A + B’ + C + D)
= (A' + A'D' + A'B' + A'D) (A + AB' + AC + AD + AB + BC + BD + AD' + B'D' + CD')
= A'(1 + D' + B' + D) (A(1 + B' + C + D + B + D') + BC + BD + B'D' + CD')
= A' (A + BC + BD + B'D' + CD')
= A'BC + A'BD + A'B'D' + A'CD'

(which is the reqd. SOP form)