Recent questions tagged relations

5 5 votes
1 1 answer
296
296 views
Consider the relation schema $R(A,B,C)$.The domain sizes of the attributes are:$|D_A|=2$$|D_B|=2$$|D_C|=3$Assume that there are no constraints other than the domain const...
1 1 vote
1 1 answer
147
147 views
Which one of the following statements about the pure relational model and its database implementation is correct?A relation in the relational model is represented concept...
1 1 vote
1 1 answer
152
152 views
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason RAssertion A: Let $\mathrm{R} \subseteq \mathrm{A} \times \mathrm{A}$ b...
11 11 votes
3 3 answers
1.7k
1.7k views
Let $R$ be a binary relation on the set $\{1,2, \ldots, 10\}$, where $(x, y) \in R$ if the product of $x$ and $y$ is square of an integer. Which of the following properti...
4 4 votes
0 0 answers
469
469 views
Let $R$ be a binary relation on the set $A=\{1,2, \ldots, 10\}$ defined by$R = \{(x, y) \mid x.y = k^2, k \in N\}$Which of the following properties does $R$ satisfy?Symme...
0 0 votes
2 answers 2 answers
342
342 views
Given relation S, where S = {(x,y) | y divides x) on Z⁻ (set of negative integers). Is S reflexive?
0 0 votes
2 2 answers
412
412 views
Consider the following relations on $\{1,2,3,4\}$. Which of the following relations are reflexive?$\mathrm{R}_{1}=\{(1,1),(1,2),(2,1),(2,2),(3,4),(4,1),(4,4)\}$$\mathrm{R...
0 0 votes
0 0 answers
184
184 views
If $N^{2}=N \times N$, $N$ is set of natural numbers and $R$ is relation on $N^{2}$, s.t. $R C N^{2} \times N^{2}$ i.e. $<x, y>$ $R <u, v \Leftrightarrow x v = y u$, then...
1 1 vote
0 0 answers
102
102 views
Let $X=\{1,2,3,4\}$. If$\mathrm{A}=\{\langle x, y\rangle \mid x \in X \wedge y \in X \wedge(x-y)$ is a nonzero multiple of 2$\}$$\mathrm{B}=\{\langle x, y\rangle \mid x \...
2 2 votes
4 4 answers
737
737 views
Let $R=\{(1,2),(2,3),(3,3)\}$ be a relation defined on the set $\{1,2,3,4\}$. Then the minimum number of elements, needed to be added in $R$ so that R becomes an equivale...
2 2 votes
4 4 answers
480
480 views
The relation $R=\{(x, y): x, y \in \mathbb{Z}$ and $x+y$ is even $\}$ is:reflexive and transitive but not symmetric reflexive and symmetric but not transitive an equivale...
1 1 vote
3 3 answers
608
608 views
Let $\mathbf{A}=\{0,1,2,3,4,5\}$. Let $\mathbf{R}$ be a relation on $\mathbf{A}$ defined by $(\mathrm{x}, \mathrm{y}) \in \mathbf{R}$ if and only if $\max \{\mathrm{x}, \...
0 0 votes
0 0 answers
203
203 views
A binary relation $R$ defined on a set $S$ is said to be antisymmetric if for $x, y \in S,$ $x R y$ and $y R x \Longrightarrow x=y$. Let $R_{1}, R_{2}$ be two binary rela...
1 1 vote
3 3 answers
440
440 views
Let $R=\{(3,3),(6,6),(9,9),(12,12),(6,12),(3,9),(3,12),(3,6)\}$ be a relation on the set $A=$ $\{3,6,9,12\}$. The relation $R$ is:Reflexive and transitiveReflexive onlyAn...
0 0 votes
1 answers 1 answer
317
317 views
Let A be a set with |A| = n, and let R be an equivalence relation on set A with |R| = r. Which of the following is/are TURE?(A) r – n will always be even.(B) r – n will a...
29 29 votes
5 5 answers
6.7k
6.7k views
​​Let $\mathcal{F}$ be the set of all functions from $\{1, \ldots, n\}$ to $\{0,1\}$. Define the binary relation $\leqslant$ on $\mathcal{F}$ as follows:$\forall f, g \in...
1 1 vote
2 2 answers
425
425 views
Visualizing Types of Relation in the form of Venn Diagram so that we can which relation can subset of whom , who are pairwise disjoint and who are proper subsets only an...
1 1 vote
1 1 answer
687
687 views
 Can someone help me out in giving example for each, For Example 1:N Both Mandatory : Person->No of Classes Attended, This can be (PersonName,ClassName) but how is the nu...
3 3 votes
1 answers 1 answer
638
638 views
Can Somebody help me solve these recurrences?What is the method generally employed to solve questions of this type?Taken from https://jeffe.cs.illinois.edu/teaching/algor...