Let a be the set of students at your school and b the set of books in the school library. let r₁ and r₂ be the relations consisting of all ordered pairs (a, b), where student a is required to read book b in a course, and where student a has read book b, respectively. describe the ordered pairs in each of these relations.

a) r₁ ∪ r₂
b) r₁ ∩ r₂
c) r₁ ⊕ r₂
d) r₁ − r₂
e) r₂ − r₁

a) {(a,b)[a is required to read book b or has read book b]}

b) {(a,b)[a has read book b that he was required to read)]

c) {(a,b)[a is either required to read book b or has read it but he has not read both)]

d) {(a,b)[a is required to read book b and he is yet to read book b)]

e) {(a,b)[a has read book b that was not required)]

Step-by-step explanation: The answers is a description of the explanation