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 $R=\{x:(x$, $y)\in R\}=\{-2$, $-1$, $0$, $1$, $2\}$