Suppose that R is the following relation on the set A = {1,2,3,4}: R = A × A – {(1, 1), (2, 2), (3, 3), (4,4)} Determine which of the following is the relation R². OR1. R1 = A × A R2. R2 = {} R3. R3=R

. A relation R on a set S, defined as x R y if and only if y R x. This is an example of?a) reflexive relationb) symmetric relationc) transitive relationd) invalid relation

11 of 40 Consider the following Relation instance of Students: ID firstNamelastName GPA Address 123 Albertson Albertson 3.5 888 CDN 234 Mary Albertson 4.2 759 St. Catherine Est. 345 Smith Smith 2.9 105 Queen Mary 456 Theodore McDonald 3.7 208 Jean Talon West 567 Jean Mary 3.9 950 Des Laurentides 678 Junior Junior 4.1 326 St. Martin West How many records will be in the result of the following SQL Query? Select ID, firstName From Students S Where firstName = lastName and firstName NOT IN ( Select lastName From Students Where ID S.ID); Answer:

3. Consider the following set F of functional dependencies on R = ABCDEG. F = {A-> BCD, BC -> DE, B -> D, D -> A) Compute B+.