A relation on the set A=x : |x|

Question

A relation on the set $A=\{x : |x|<3,\ x\in\mathbb{Z}\}$, where $\mathbb{Z}$ is the set of integers, is defined by $R=\{(x,y) : y=|x|,\ x
eq-1\}$. Then the number of elements in the power set of $R$ is:

Accepted Answer

$A=\{-2,-1,0,1,2\}$. Excluding $x=-1$, the pairs $(x,|x|)$ are:
$$R=\{(-2,2),(0,0),(1,1),(2,2)\}$$
$R$ has 4 elements, so the power set of $R$ has $2^4=16$ elements.

Solutions · 1