Question

Which of the following is a singleton set?

• A. $\{x:|x|<1, x \in Z\}$
• B. $\{x:|x|=5, x \in Z \}$
• C. $\left\{x: x^{2}=1, x \in Z\right\}$
• D. $\left\{x: x^{2}+x+1=0, x \in R\right\}$

Answer 1

Answer: (A)

$|x|< 1 \Rightarrow -1< x< 1 $
($x=0$ integer satisfies it )