A B C is a set of attributes. The functional dependency is as follows
AB -> B
AC -> C
C -> B
a) is in 1NF
b) is in 2NF
c) is in 3NF
d) is in BCNF

• is in 1NF
  HERE AC IS CANDIDATE KEY BUT BUT NON PRIME ATTRIBUTE B IS NOT FULLY FUNCTIONALLY DEPENDENT ON AC IT DEPENDS ON PARTIAL ATTRIBUTE C OF CANDIDATE KEY AC.
• 10 years agoHelpfull: Yes(4) No(0)
• a)is in 1NF
  is in 1NF since (AC)+ = { A, B, C} hence AC is the primary key. Since C B is a FD given, where neither C is a Key nor B is a prime attribute, this it is not in 3NF. Further B is not functionally dependent on key AC thus it is not in 2NF. Thus the given FDs is in 1NF.
  
• 10 years agoHelpfull: Yes(1) No(0)
• this functional dependency is in 3 NF as there is no transitive or partial dependency,
  the candidate keys here are AB and AC.
• 10 years agoHelpfull: Yes(0) No(1)