Which of the following is not correct for relation $\mathrm{R}$ on the set of real numbers ?
$(\mathrm{x}, \mathrm{y}) \in \mathrm{R} \Leftrightarrow 0<|\mathrm{x}|-|\mathrm{y}| \leq 1$ is neither transitive nor symmetric.
$(x, y) \in R \Leftrightarrow 0<|x-y| \leq 1$ is symmetric and transitive.
$(x, y) \in R \Leftrightarrow|x|-|y| \leq 1$ is reflexive but not symmetric.
$(\mathrm{x}, \mathrm{y}) \in \mathrm{R} \Leftrightarrow|\mathrm{x}-\mathrm{y}| \leq 1$ is reflexive and symmetric.
Let $A=\{-4,-3,-2,0,1,3,4\}$ and $R =\{( a , b ) \in A$ $\times A : b =| a |$ or $\left.b ^2= a +1\right\}$ be a relation on $A$. Then the minimum number of elements, that must be added to the relation $R$ so that it becomes reflexive and symmetric, is $........$.
The void relation on a set $A$ is
Let $R_{1}$ and $R_{2}$ be two relations defined on $R$ by $a R _{1} b \Leftrightarrow a b \geq 0$ and $a R_{2} b \Leftrightarrow a \geq b$, then
Show that the relation $R$ in the set $\{1,2,3\}$ given by $R =\{(1,1),\,(2,2),$ $(3,3)$, $(1,2)$, $(2,3)\}$ is reflexive but neither symmetric nor transitive.
Let $R$ be a relation on the set $N$ of natural numbers defined by $nRm $$\Leftrightarrow$ $n$ is a factor of $m$ (i.e.,$ n|m$). Then $R$ is