Obtain a truth table for each of the following functions and express each function as sumof-minterms and product-of-maxterms. a. Fa(b, c, d) = (b + cd)(c + bd) b. Fb(a, b, c, d) = (cd + bc + bd)(b + d) c. Fc(b, c, d) = (c + d)(b + c) d. Fd (a,b, c, d) = bd + acd + abc +ac