1. Defined below are three relations' schemas and their sets of functional dependencies.

R₁(A, B, C, D)

A → BCD

C → AB

R₂(E, F, G, H, I, J, K)

E → FG

EFG H

R₁(L, M, N, O, P, R)

L MN

LN → OPR

R → LM

a) For each of the relations R₁, R₂, and R3, check which of the following are candidate keys (can be

more than one for each relation, or none).

R₁: A, B, C, D, AB, BC, ABC

R₂: E, FG, EFG, EIJK

R₁: L, N, R, LN, MR, NMR

b) For each of the relations R₁, R₂, and R, determine if it is in 3NF.

c) For each of the relations R₁, R2, and R3 determine if it is in BCNF.