Question

If R = {(x, y) : x² + y² ≤ 4; x, y ∈ Z} is a relation on Z, write the domain of R.

Answer 1

Domain of R is the set of values of x satisfying the relation R.
As x must be an integer, we get the given values of x:

$$\begin{gathered} 0,\pm 1,\pm 2 \\ \mathrm{Thus}, \\ \mathrm{Domain}\mathrm{of}R=\left\{0,\pm 1,\pm 2\right\} \end{gathered}$$