DMS Sunita M Dol
Walchand Institute of Technology, Solapur Page 1
Assignment No. 9
Topics covered:
• Relations
• Properties of binary relations
• Matrix and graph representation
1. Let P = {<1, 2>, <2, 4>, <3, 3>} and Q = {<1, 3>, <2, 4>, <4, 2>}. Find
a. P ∪ Q,
b. P ∩ Q,
c. D(P),
d. D(Q),
e. D(P ∪ Q),
f. R(P),
g. R(Q) and
h. R(P ∩ Q).
Show that
D(P ∪ Q) = D(P) ∪ D(Q) and
R(P ∩ Q) ⊆ R(P) ∩ R (Q)
2. What are the ranges of the relations
S = {<x, x2> | x ∈ N}
R = {<x, 2x> | x ∈ N}
where N = {0, 1, 2, 3, …}? Find R ∪ S and R ∩ S
3. Let L denote the relation “less than or equal to” and D denote the relation
“divides” where xDy means “x divides y”. Both L and D are defined on the
set {1, 2, 3, 6}. Write L and D sets and find L ∩ D.
4. Give an example of a relation which is neither reflexive nor Irreflexive.
5. Give an example of a relation which is both symmetric and Antisymmetric.
DMS Sunita M Dol
Walchand Institute of Technology, Solapur Page 2
6. Show that whether the following relations are transitive
R1 = {<1, 1>}
R2 = {<1, 2>, <2, 2>}
R3 = {<1, 2>, <2, 3>, <1, 3>, <2, 1>}
7. Given S = {1, 2, 3, 4} and a relation R on S defined by
R = {<1, 2>, <4, 3>, <2, 2>, <2, 1>, <3, 1>}
Show that R is not transitive. Find a relation R1 ⊇ R such that R1 is
transitive. Can you find another relation R2 ⊇ R which is also transitive?
8. Given S = {1, 2, …, 10} and a relation R on S where
R = {<x, y> | x + y = 10}
What are the properties of the relation R?

Assignment No. 9 on Unit-IV Set Theory, Relations and Function

  • 1.
    DMS Sunita MDol Walchand Institute of Technology, Solapur Page 1 Assignment No. 9 Topics covered: • Relations • Properties of binary relations • Matrix and graph representation 1. Let P = {<1, 2>, <2, 4>, <3, 3>} and Q = {<1, 3>, <2, 4>, <4, 2>}. Find a. P ∪ Q, b. P ∩ Q, c. D(P), d. D(Q), e. D(P ∪ Q), f. R(P), g. R(Q) and h. R(P ∩ Q). Show that D(P ∪ Q) = D(P) ∪ D(Q) and R(P ∩ Q) ⊆ R(P) ∩ R (Q) 2. What are the ranges of the relations S = {<x, x2> | x ∈ N} R = {<x, 2x> | x ∈ N} where N = {0, 1, 2, 3, …}? Find R ∪ S and R ∩ S 3. Let L denote the relation “less than or equal to” and D denote the relation “divides” where xDy means “x divides y”. Both L and D are defined on the set {1, 2, 3, 6}. Write L and D sets and find L ∩ D. 4. Give an example of a relation which is neither reflexive nor Irreflexive. 5. Give an example of a relation which is both symmetric and Antisymmetric.
  • 2.
    DMS Sunita MDol Walchand Institute of Technology, Solapur Page 2 6. Show that whether the following relations are transitive R1 = {<1, 1>} R2 = {<1, 2>, <2, 2>} R3 = {<1, 2>, <2, 3>, <1, 3>, <2, 1>} 7. Given S = {1, 2, 3, 4} and a relation R on S defined by R = {<1, 2>, <4, 3>, <2, 2>, <2, 1>, <3, 1>} Show that R is not transitive. Find a relation R1 ⊇ R such that R1 is transitive. Can you find another relation R2 ⊇ R which is also transitive? 8. Given S = {1, 2, …, 10} and a relation R on S where R = {<x, y> | x + y = 10} What are the properties of the relation R?