Question

If $R = \{(x$, $y ) : x$, $y \in I$, $x^2 + y^2 \le 4\}$ is a relation in $I$, then domain of $R$ is

• A. $\{0$, $1$, $2\}$
• B. $\{-2$, $-1$, $0\}$
• C. $\{-2$, $-1$, $0$, $1$, $2\}$
• D. None of these

Answer 1

Answer: (C)

Given, $R = \{(x$, $y) :x$, $y \in I$, $x^2 + y^2 \le 4\}$
$= \{(0$, $0)$, $(0$, $-1)$, $(0$, $1)$, $(0$, $-2) ...(-2$, $0)\}$
$\therefore $ Domain of $R = \{x: (x$, $y) \in R\} = \{-2$, $-1$, $0$, $1$, $2\}$