Question

Which of the following sets :
$A=\{x:xisirrationaland{x}^2-1=0\}$.
$B=\{x:xϵzand-2\le x\le 2\}$ are empty.

Answer 1

$A=\{\begin{array}{c}x:x\\ x^2-1=0\end{array}\begin{array}{c}isirrational\\ \Rightarrow x=\pm 1\end{array}$

$B=\{\begin{array}{c}x:xz\\ value\end{array}\begin{array}{c}and-2\le x\le 2\\ exist\end{array}$

empty set.