Consider the following Boolean functions:

f (a, b, c) = ab + ac + abc

f (a, b, c, d) = (b + d) (a + b + c)

a) Draw the circuit for each function f using AND, OR and NOT gates.

b) Write the truth table for each function.

c) Express the functions in the sum of products (SOP) form. (Minimization not required).

d) Express the functions in the product of sums (POS) form (Minimization not required).