1. Compute the closure of the following set F of functional dependencies for the schema R=(A,B, C,D,E) and list the candidate keys of R. F= A-gt BC,CD-gt E,Barrow D,Earrow A 2. Using Fin question 1 compute the attribute closure of B (Find B^+) F= A-gt BC,CD-gt E,B-gt D,E-gt A

1. The closure of a set of functional dependencies is the set of all attributes that can be determined from the given functional dependencies. In this case, we have the functional dependencies $F=\{ A\rightarrow BC,CD\rightarrow E,B\rightarrow D,E\rightarrow A\}$. To find the closure of this set, we start with the attributes on the right-hand side of each functional dependency and add any attributes that can be determined from the functional dependencies. We continue this process until no new attributes can be added. The closure of $F$ is $\{A,B,C,D,E\}$, which is the set of all attributes in the schema $R=(A,B,C,D,E)$. The candidate keys of $R$ are the sets of attributes that determine all other attributes in the schema. In this case, the candidate keys are $\{A,B,C\}$ and $\{A,B,D\}$.<br />2. The attribute closure of $B$, denoted as $B^{+}$, is the set of all attributes that can be determined from $B$ using the functional dependencies in $F$. We start with $B$ and add any attributes that can be determined from the functional dependencies. We continue this process until no new attributes can be added. In this case, $B^{+}=\{A,B,C,D,E\}$.