13. If R = {x, y)/x = 2y} is a relation defined on A = {1, 2, 3, 4, 6,

1.	13. If R = {x, y)/x = 2y} is a relation defined on A = {1, 2, 3, 4, 6, 7, 8} then write all elements of R Alsowrite its Domain and Range?
Answer» $\textbf{Given:}$ $A=\{1,2,3,4,6,7,8\}$ $\textbf{To find:}$ $\text{Elements of R, domain and range}$ $\textbf{Solution:}$ $x=2y\implies\,y=\dfrac{x}{2}$ $\text{when x=2,}\,y=\dfrac{2}{2}=1$ $\implies\,(2,1)\,\in\,R$ $\text{when x=4,}\,y=\dfrac{4}{2}=2$ $\implies\,(4,2)\,\in\,R$ $\text{when x=6,}\,y=\dfrac{6}{2}=3$ $\implies\,(6,3)\,\in\,R$ $\text{when x=8,}\,y=\dfrac{8}{2}=4$ $\implies\,(8,4)\,\in\,R$ $\therefore\bf\,R=\{(2,1),(4,2),(6,3),(8,4)\}$ $\textbf{Domain}=\{2,4,6,8\}$ $\textbf{Range}=\{1,2,3,4\}$