Question

If a set A is defined as $A=\{x:x^2-9\ne 0,\forall xϵ$ integers}, calculate, the elements of set A.

Answer 1

Since,
$x^2-9\ne 0$
$x^2\ne 9$
$x^2\ne \pm 3$
$\therefore A=\{0,\pm 1,\pm 2,\pm 4,\pm 5........\}$