Question

Check whether the sets $A$ and $B$ are disjoint:
$A$ is the set of all perfect squares, $B$ is the set of all negative integers

Answer 1

$A=\{1,4,9,\mathrm{16.......}\}$

$B=\{-1,-2,-3,-4,-\mathrm{5........}\}$

$A\cap B=\varphi$

So , A and B are disjoint sets.