Question

Let A = {1, 2, 3,....., 14}. Define a relation R from A to A by R = {(x, y): 3x - y = 0, where $x,yϵA$} Write down its domain, codomain and range.

Answer 1

Here A = {1, 2, 3,....14}.

We shall consider the ordered pairs which satisfy 3x - y = 0.

They are (1, 3), (2, 6), (3, 9) and (4, 12).

Thus R = {(1, 3), (2, 6), (3, 9), (4, 12)}

$\therefore$ Domain = {1, 2, 3, 4}

Range = {3, 6, 9, 12}

Co-domain = {1, 2, 3, ......, 14}