(A)Give a Set of Functional Dependencies for the Relational Schema $\rightarrow$

Essay

(a)Give a set of functional dependencies for the relational schema R(A, B, C, D) with primary key AB under which R is in 1NF but not in 2NF.
(b) Give a set of functional dependencies for the relational schema R(A, B, C, D) with primary key AB under which R is in 2NF but not in 3NF.
(c) Consider a relational schema R(A, B, C) with a functional dependency B $\rightarrow$ C. If A is a candidate key of R, could R be in BCNF and, if so, under what conditions?